diff --git a/core/Cargo.toml b/core/Cargo.toml
index d76cd3d2..d4b35f09 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -15,8 +15,9 @@ rust-version = "1.73.0"
 crate-type = ["rlib", "cdylib"]
 
 [features]
-default = []
+default = ["city-name-correction"]
 blocking = ["reqwest/blocking"]
+city-name-correction = []
 
 [dependencies]
 itertools = "0.13.0"
diff --git a/core/src/lib.rs b/core/src/lib.rs
index 63fe3cbb..f340ca78 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -1,3 +1,9 @@
+//! A Rust library to parse japanese addresses.
+//!
+//! ## Feature flags
+//! - `blocking`: Provide method that works synchronously
+//! - `city-name-correction`*(enabled by default)*: Enable autocorrection if ambiguous city name was typed
+
 #[cfg(all(target_family = "wasm", feature = "blocking"))]
 compile_error! {
     "The `blocking` feature is not supported with wasm target."
diff --git a/core/src/parser.rs b/core/src/parser.rs
index c51eed3b..7245e1fe 100644
--- a/core/src/parser.rs
+++ b/core/src/parser.rs
@@ -98,11 +98,21 @@ pub async fn parse(api: Arc<AsyncApi>, input: &str) -> ParseResult {
         Ok(result) => result,
     };
     // 市町村名を特定
-    let Ok(tokenizer) = tokenizer.read_city(prefecture.cities) else {
-        return ParseResult {
-            address: Address::from(tokenizer),
-            error: Some(Error::new_parse_error(ParseErrorKind::City)),
-        };
+    let tokenizer = match tokenizer.read_city(&prefecture.cities) {
+        Ok(found) => found,
+        Err(not_found) => {
+            // 市区町村が特定できない場合かつフィーチャフラグが有効な場合、郡名が抜けている可能性を検討
+            match not_found.read_city_with_county_name_completion(&prefecture.cities) {
+                Ok(found) if cfg!(feature = "city-name-correction") => found,
+                _ => {
+                    // それでも見つからない場合は終了
+                    return ParseResult {
+                        address: Address::from(tokenizer),
+                        error: Some(Error::new_parse_error(ParseErrorKind::City)),
+                    };
+                }
+            }
+        }
     };
     // その市町村の町名リストを取得
     let city = match api
@@ -254,11 +264,19 @@ pub fn parse_blocking(api: Arc<BlockingApi>, input: &str) -> ParseResult {
         }
         Ok(result) => result,
     };
-    let Ok(tokenizer) = tokenizer.read_city(prefecture.cities) else {
-        return ParseResult {
-            address: Address::from(tokenizer),
-            error: Some(Error::new_parse_error(ParseErrorKind::City)),
-        };
+    let tokenizer = match tokenizer.read_city(&prefecture.cities) {
+        Ok(found) => found,
+        Err(not_found) => {
+            match not_found.read_city_with_county_name_completion(&prefecture.cities) {
+                Ok(found) if cfg!(feature = "city-name-correction") => found,
+                _ => {
+                    return ParseResult {
+                        address: Address::from(tokenizer),
+                        error: Some(Error::new_parse_error(ParseErrorKind::City)),
+                    };
+                }
+            }
+        }
     };
     let city = match api.get_city_master(
         tokenizer.prefecture_name.as_ref().unwrap(),
diff --git a/core/src/parser/adapter.rs b/core/src/parser/adapter.rs
index d64fc3c0..f606829f 100644
--- a/core/src/parser/adapter.rs
+++ b/core/src/parser/adapter.rs
@@ -1,2 +1 @@
 pub mod orthographical_variant_adapter;
-pub mod vague_expression_adapter;
diff --git a/core/src/parser/adapter/vague_expression_adapter.rs b/core/src/parser/adapter/vague_expression_adapter.rs
deleted file mode 100644
index badec48f..00000000
--- a/core/src/parser/adapter/vague_expression_adapter.rs
+++ /dev/null
@@ -1,122 +0,0 @@
-use crate::util::sequence_matcher::SequenceMatcher;
-
-pub struct VagueExpressionAdapter;
-
-impl VagueExpressionAdapter {
-    pub fn apply(self, input: &str, region_name_list: &[String]) -> Option<(String, String)> {
-        if let Ok(highest_match) =
-            SequenceMatcher::get_most_similar_match(input, region_name_list, None)
-        {
-            if let Ok(complemented_address) = complement_county_name(input, &highest_match) {
-                return Some((
-                    highest_match.clone(),
-                    complemented_address
-                        .chars()
-                        .skip(highest_match.chars().count())
-                        .collect(),
-                ));
-            }
-        }
-        None
-    }
-}
-
-/// 郡名が抜けている住所に郡名を補う関数
-///
-/// 欠けている郡名を補うだけで、それ以上のことはしない。
-/// 市区町村名に表記揺れがあってもそれを上書きすることはしない。
-fn complement_county_name(vague_address: &str, with: &str) -> Result<String, &'static str> {
-    match with.chars().position(|c| c == '郡') {
-        None => Err("郡名が見つかりませんでした"),
-        Some(position) => Ok(with.chars().take(position + 1).collect::<String>() + vague_address),
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::domain::geolonia::entity::Prefecture;
-    use crate::parser::adapter::vague_expression_adapter::{
-        complement_county_name, VagueExpressionAdapter,
-    };
-
-    #[test]
-    fn complement_county_name_郡名が省略されている場合() {
-        assert_eq!(
-            complement_county_name("大町町大字福母297", "杵島郡大町町").unwrap(),
-            "杵島郡大町町大字福母297"
-        );
-        assert_eq!(
-            complement_county_name("村田町大字村田字迫6", "柴田郡村田町").unwrap(),
-            "柴田郡村田町大字村田字迫6"
-        );
-        assert_eq!(
-            complement_county_name("玉村町上新田1116", "佐波郡玉村町").unwrap(),
-            "佐波郡玉村町上新田1116"
-        );
-        // 市区町村名に表記揺れも含む場合
-        assert_eq!(
-            complement_county_name("桧原村上元郷403", "西多摩郡檜原村").unwrap(),
-            "西多摩郡桧原村上元郷403"
-        )
-    }
-
-    #[test]
-    fn 郡名が省略されている場合_吉田郡永平寺町() {
-        let fukui = Prefecture::fukui();
-        let (city_name, rest) = VagueExpressionAdapter {}
-            .apply("永平寺町志比５－５", &fukui.cities)
-            .unwrap();
-        assert_eq!(city_name, "吉田郡永平寺町");
-        assert_eq!(rest, "志比５－５");
-    }
-
-    #[test]
-    fn 郡名が省略されている場合_今立郡池田町() {
-        let fukui = Prefecture::fukui();
-        let (city_name, rest) = VagueExpressionAdapter {}
-            .apply("池田町稲荷２８－７", &fukui.cities)
-            .unwrap();
-        assert_eq!(city_name, "今立郡池田町");
-        assert_eq!(rest, "稲荷２８－７");
-    }
-
-    #[test]
-    fn 郡名が省略されている場合_南条郡南越前町() {
-        let fukui = Prefecture::fukui();
-        let (city_name, rest) = VagueExpressionAdapter {}
-            .apply("南越前町今庄７４－７－１", &fukui.cities)
-            .unwrap();
-        assert_eq!(city_name, "南条郡南越前町");
-        assert_eq!(rest, "今庄７４－７－１");
-    }
-
-    #[test]
-    fn 郡名が省略されている場合_西村山郡河北町() {
-        let yamagata = Prefecture::yamagata();
-        let (city_name, rest) = VagueExpressionAdapter {}
-            .apply("河北町大字吉田字馬場261", &yamagata.cities)
-            .unwrap();
-        assert_eq!(city_name, "西村山郡河北町");
-        assert_eq!(rest, "大字吉田字馬場261");
-    }
-
-    #[test]
-    fn 郡名が省略されている場合_杵島郡大町町() {
-        let saga = Prefecture::saga();
-        let (city_name, rest) = VagueExpressionAdapter {}
-            .apply("大町町大字大町5017番地", &saga.cities)
-            .unwrap();
-        assert_eq!(city_name, "杵島郡大町町");
-        assert_eq!(rest, "大字大町5017番地");
-    }
-
-    #[test]
-    fn 郡名と町名が一致している場合_最上郡最上町() {
-        let yamagata = Prefecture::yamagata();
-        let (city_name, rest) = VagueExpressionAdapter {}
-            .apply("最上町法田2672-2", &yamagata.cities)
-            .unwrap();
-        assert_eq!(city_name, "最上郡最上町");
-        assert_eq!(rest, "法田2672-2");
-    }
-}
diff --git a/core/src/tokenizer.rs b/core/src/tokenizer.rs
index 0a4c9af7..aa305502 100644
--- a/core/src/tokenizer.rs
+++ b/core/src/tokenizer.rs
@@ -1,4 +1,5 @@
 pub(crate) mod read_city;
+pub(crate) mod read_city_with_county_name_completion;
 pub(crate) mod read_prefecture;
 pub(crate) mod read_town;
 
@@ -11,6 +12,8 @@ pub(crate) struct PrefectureNameFound;
 #[derive(Debug)]
 pub(crate) struct CityNameFound;
 #[derive(Debug)]
+pub(crate) struct CityNameNotFound;
+#[derive(Debug)]
 pub(crate) struct TownNameFound;
 #[derive(Debug)]
 pub(crate) struct End;
diff --git a/core/src/tokenizer/read_city.rs b/core/src/tokenizer/read_city.rs
index a882d618..4c865f14 100644
--- a/core/src/tokenizer/read_city.rs
+++ b/core/src/tokenizer/read_city.rs
@@ -3,15 +3,14 @@ use std::marker::PhantomData;
 use crate::parser::adapter::orthographical_variant_adapter::{
     OrthographicalVariantAdapter, OrthographicalVariants, Variant,
 };
-use crate::parser::adapter::vague_expression_adapter::VagueExpressionAdapter;
-use crate::tokenizer::{CityNameFound, End, PrefectureNameFound, Tokenizer};
+use crate::tokenizer::{CityNameFound, CityNameNotFound, PrefectureNameFound, Tokenizer};
 
 impl Tokenizer<PrefectureNameFound> {
     pub(crate) fn read_city(
         &self,
-        candidates: Vec<String>,
-    ) -> Result<Tokenizer<CityNameFound>, Tokenizer<End>> {
-        for candidate in &candidates {
+        candidates: &Vec<String>,
+    ) -> Result<Tokenizer<CityNameFound>, Tokenizer<CityNameNotFound>> {
+        for candidate in candidates {
             if self.rest.starts_with(candidate) {
                 return Ok(Tokenizer {
                     input: self.input.clone(),
@@ -69,26 +68,13 @@ impl Tokenizer<PrefectureNameFound> {
             }
         }
 
-        // ここまでで市町村名の特定ができない場合はVagueExpressionAdapterを使用して市町村名を推測する
-        let vague_expression_adapter = VagueExpressionAdapter {};
-        if let Some(result) = vague_expression_adapter.apply(self.rest.as_str(), &candidates) {
-            return Ok(Tokenizer {
-                input: self.input.clone(),
-                prefecture_name: self.prefecture_name.clone(),
-                city_name: Some(result.0),
-                town_name: None,
-                rest: result.1,
-                _state: PhantomData::<CityNameFound>,
-            });
-        }
-
         Err(Tokenizer {
             input: self.input.clone(),
             prefecture_name: self.prefecture_name.clone(),
             city_name: None,
             town_name: None,
             rest: self.rest.clone(),
-            _state: PhantomData::<End>,
+            _state: PhantomData::<CityNameNotFound>,
         })
     }
 }
@@ -108,7 +94,7 @@ mod tests {
             rest: "横浜市保土ケ谷区川辺町2番地9".to_string(),
             _state: PhantomData::<PrefectureNameFound>,
         };
-        let result = tokenizer.read_city(vec![
+        let result = tokenizer.read_city(&vec![
             "横浜市保土ケ谷区".to_string(),
             "横浜市鶴見区".to_string(),
             "横浜市西区".to_string(),
@@ -132,7 +118,7 @@ mod tests {
             rest: "横浜市保土ヶ谷区川辺町2番地9".to_string(),
             _state: PhantomData::<PrefectureNameFound>,
         };
-        let result = tokenizer.read_city(vec![
+        let result = tokenizer.read_city(&vec![
             "横浜市保土ケ谷区".to_string(),
             "横浜市鶴見区".to_string(),
             "横浜市西区".to_string(),
@@ -146,31 +132,6 @@ mod tests {
         assert_eq!(tokenizer.rest, "川辺町2番地9");
     }
 
-    #[test]
-    fn read_city_vague_expression_adapterで成功() {
-        let tokenizer = Tokenizer {
-            input: "埼玉県東秩父村大字御堂634番地".to_string(), // 「秩父郡」が省略されている
-            prefecture_name: Some("埼玉県".to_string()),
-            city_name: None,
-            town_name: None,
-            rest: "東秩父村大字御堂634番地".to_string(),
-            _state: PhantomData::<PrefectureNameFound>,
-        };
-        let result = tokenizer.read_city(vec![
-            "秩父郡皆野町".to_string(),
-            "秩父郡長瀞町".to_string(),
-            "秩父郡小鹿野町".to_string(),
-            "秩父郡東秩父村".to_string(),
-        ]);
-        assert!(result.is_ok());
-        let tokenizer = result.unwrap();
-        assert_eq!(tokenizer.input, "埼玉県東秩父村大字御堂634番地");
-        assert_eq!(tokenizer.prefecture_name, Some("埼玉県".to_string()));
-        assert_eq!(tokenizer.city_name, Some("秩父郡東秩父村".to_string()));
-        assert_eq!(tokenizer.town_name, None);
-        assert_eq!(tokenizer.rest, "大字御堂634番地");
-    }
-
     #[test]
     fn read_city_失敗() {
         let tokenizer = Tokenizer {
@@ -181,7 +142,7 @@ mod tests {
             rest: "京都市上京区川辺町2番地9".to_string(),
             _state: PhantomData::<PrefectureNameFound>,
         };
-        let result = tokenizer.read_city(vec![
+        let result = tokenizer.read_city(&vec![
             "横浜市保土ケ谷区".to_string(),
             "横浜市鶴見区".to_string(),
             "横浜市西区".to_string(),
diff --git a/core/src/tokenizer/read_city_with_county_name_completion.rs b/core/src/tokenizer/read_city_with_county_name_completion.rs
new file mode 100644
index 00000000..b666c82f
--- /dev/null
+++ b/core/src/tokenizer/read_city_with_county_name_completion.rs
@@ -0,0 +1,205 @@
+use crate::tokenizer::{CityNameFound, CityNameNotFound, End, Tokenizer};
+use crate::util::sequence_matcher::SequenceMatcher;
+use std::marker::PhantomData;
+
+impl Tokenizer<CityNameNotFound> {
+    pub(crate) fn read_city_with_county_name_completion(
+        &self,
+        candidates: &[String],
+    ) -> Result<Tokenizer<CityNameFound>, Tokenizer<End>> {
+        if let Ok(highest_match) =
+            SequenceMatcher::get_most_similar_match(&self.rest, candidates, None)
+        {
+            if let Ok(complemented_address) = complement_county_name(&self.rest, &highest_match) {
+                return Ok(Tokenizer {
+                    input: self.input.clone(),
+                    prefecture_name: self.prefecture_name.clone(),
+                    city_name: Some(highest_match.clone()),
+                    town_name: None,
+                    rest: complemented_address
+                        .chars()
+                        .skip(highest_match.chars().count())
+                        .collect(),
+                    _state: PhantomData::<CityNameFound>,
+                });
+            }
+        }
+        Err(Tokenizer {
+            input: self.input.clone(),
+            prefecture_name: self.prefecture_name.clone(),
+            city_name: None,
+            town_name: None,
+            rest: self.rest.clone(),
+            _state: PhantomData::<End>,
+        })
+    }
+}
+
+/// 郡名が抜けている住所に郡名を補う関数
+///
+/// 欠けている郡名を補うだけで、それ以上のことはしない。
+/// 市区町村名に表記揺れがあってもそれを上書きすることはしない。
+fn complement_county_name(vague_address: &str, with: &str) -> Result<String, &'static str> {
+    match with.chars().position(|c| c == '郡') {
+        None => Err("郡名が見つかりませんでした"),
+        Some(position) => Ok(with.chars().take(position + 1).collect::<String>() + vague_address),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::domain::geolonia::entity::Prefecture;
+    use crate::tokenizer::read_city_with_county_name_completion::complement_county_name;
+    use crate::tokenizer::{CityNameNotFound, Tokenizer};
+    use std::marker::PhantomData;
+
+    #[test]
+    fn complement_county_name_郡名が省略されている場合() {
+        assert_eq!(
+            complement_county_name("大町町大字福母297", "杵島郡大町町").unwrap(),
+            "杵島郡大町町大字福母297"
+        );
+        assert_eq!(
+            complement_county_name("村田町大字村田字迫6", "柴田郡村田町").unwrap(),
+            "柴田郡村田町大字村田字迫6"
+        );
+        assert_eq!(
+            complement_county_name("玉村町上新田1116", "佐波郡玉村町").unwrap(),
+            "佐波郡玉村町上新田1116"
+        );
+        // 市区町村名に表記揺れも含む場合
+        assert_eq!(
+            complement_county_name("桧原村上元郷403", "西多摩郡檜原村").unwrap(),
+            "西多摩郡桧原村上元郷403"
+        )
+    }
+
+    #[test]
+    fn read_city_with_county_name_completion_秩父郡東秩父村() {
+        let tokenizer = Tokenizer {
+            input: "埼玉県東秩父村大字御堂634番地".to_string(), // 「秩父郡」が省略されている
+            prefecture_name: Some("埼玉県".to_string()),
+            city_name: None,
+            town_name: None,
+            rest: "東秩父村大字御堂634番地".to_string(),
+            _state: PhantomData::<CityNameNotFound>,
+        };
+        let result = tokenizer.read_city_with_county_name_completion(&vec![
+            "秩父郡皆野町".to_string(),
+            "秩父郡長瀞町".to_string(),
+            "秩父郡小鹿野町".to_string(),
+            "秩父郡東秩父村".to_string(),
+        ]);
+        assert!(result.is_ok());
+        let tokenizer = result.unwrap();
+        assert_eq!(tokenizer.input, "埼玉県東秩父村大字御堂634番地");
+        assert_eq!(tokenizer.prefecture_name, Some("埼玉県".to_string()));
+        assert_eq!(tokenizer.city_name, Some("秩父郡東秩父村".to_string()));
+        assert_eq!(tokenizer.town_name, None);
+        assert_eq!(tokenizer.rest, "大字御堂634番地");
+    }
+
+    #[test]
+    fn read_city_with_county_name_completion_吉田郡永平寺町() {
+        let tokenizer = Tokenizer {
+            input: "".to_string(),
+            prefecture_name: None,
+            city_name: None,
+            town_name: None,
+            rest: "永平寺町志比５－５".to_string(),
+            _state: PhantomData::<CityNameNotFound>,
+        };
+        let result = tokenizer.read_city_with_county_name_completion(&Prefecture::fukui().cities);
+        assert!(result.is_ok());
+        let tokenizer = result.unwrap();
+        assert_eq!(tokenizer.city_name, Some("吉田郡永平寺町".to_string()));
+        assert_eq!(tokenizer.rest, "志比５－５");
+    }
+
+    #[test]
+    fn read_city_with_county_name_completion_今立郡池田町() {
+        let tokenizer = Tokenizer {
+            input: "".to_string(),
+            prefecture_name: None,
+            city_name: None,
+            town_name: None,
+            rest: "池田町稲荷２８－７".to_string(),
+            _state: PhantomData::<CityNameNotFound>,
+        };
+        let result = tokenizer.read_city_with_county_name_completion(&Prefecture::fukui().cities);
+        assert!(result.is_ok());
+        let tokenizer = result.unwrap();
+        assert_eq!(tokenizer.city_name, Some("今立郡池田町".to_string()));
+        assert_eq!(tokenizer.rest, "稲荷２８－７");
+    }
+
+    #[test]
+    fn read_city_with_county_name_completion_南条郡南越前町() {
+        let tokenizer = Tokenizer {
+            input: "".to_string(),
+            prefecture_name: None,
+            city_name: None,
+            town_name: None,
+            rest: "南越前町今庄７４－７－１".to_string(),
+            _state: PhantomData::<CityNameNotFound>,
+        };
+        let result = tokenizer.read_city_with_county_name_completion(&Prefecture::fukui().cities);
+        assert!(result.is_ok());
+        let tokenizer = result.unwrap();
+        assert_eq!(tokenizer.city_name, Some("南条郡南越前町".to_string()));
+        assert_eq!(tokenizer.rest, "今庄７４－７－１");
+    }
+
+    #[test]
+    fn read_city_with_county_name_completion_西村山郡河北町() {
+        let tokenizer = Tokenizer {
+            input: "".to_string(),
+            prefecture_name: None,
+            city_name: None,
+            town_name: None,
+            rest: "河北町大字吉田字馬場261".to_string(),
+            _state: PhantomData::<CityNameNotFound>,
+        };
+        let result =
+            tokenizer.read_city_with_county_name_completion(&Prefecture::yamagata().cities);
+        assert!(result.is_ok());
+        let tokenizer = result.unwrap();
+        assert_eq!(tokenizer.city_name, Some("西村山郡河北町".to_string()));
+        assert_eq!(tokenizer.rest, "大字吉田字馬場261");
+    }
+
+    #[test]
+    fn read_city_with_county_name_completion_杵島郡大町町() {
+        let tokenizer = Tokenizer {
+            input: "".to_string(),
+            prefecture_name: None,
+            city_name: None,
+            town_name: None,
+            rest: "大町町大字大町5017番地".to_string(),
+            _state: PhantomData::<CityNameNotFound>,
+        };
+        let result = tokenizer.read_city_with_county_name_completion(&Prefecture::saga().cities);
+        assert!(result.is_ok());
+        let tokenizer = result.unwrap();
+        assert_eq!(tokenizer.city_name, Some("杵島郡大町町".to_string()));
+        assert_eq!(tokenizer.rest, "大字大町5017番地");
+    }
+
+    #[test]
+    fn read_city_with_county_name_completion_最上郡最上町() {
+        let tokenizer = Tokenizer {
+            input: "".to_string(),
+            prefecture_name: None,
+            city_name: None,
+            town_name: None,
+            rest: "最上町法田2672-2".to_string(),
+            _state: PhantomData::<CityNameNotFound>,
+        };
+        let result =
+            tokenizer.read_city_with_county_name_completion(&Prefecture::yamagata().cities);
+        assert!(result.is_ok());
+        let tokenizer = result.unwrap();
+        assert_eq!(tokenizer.city_name, Some("最上郡最上町".to_string()));
+        assert_eq!(tokenizer.rest, "法田2672-2");
+    }
+}