diff --git a/arai60/first_unique_character_in_a_string/phase1.py b/arai60/first_unique_character_in_a_string/phase1.py
new file mode 100644
index 0000000..9d95090
--- /dev/null
+++ b/arai60/first_unique_character_in_a_string/phase1.py
@@ -0,0 +1,11 @@
+class Solution:
+    def firstUniqChar(self, s: str) -> int:
+        # 登場回数を数える
+        count_appearance = [0 for _ in range(128)]
+        for char in s:
+            count_appearance[ord(char)] += 1
+
+        for index, char in enumerate(s):
+            if count_appearance[ord(char)] == 1:
+                return index
+        return -1
diff --git a/arai60/first_unique_character_in_a_string/phase2.py b/arai60/first_unique_character_in_a_string/phase2.py
new file mode 100644
index 0000000..c0f8759
--- /dev/null
+++ b/arai60/first_unique_character_in_a_string/phase2.py
@@ -0,0 +1,35 @@
+"""
+reference
+Exzrgsさん: https://github.com/Exzrgs/LeetCode/pull/9/files 命名を参考にした
+hayashi-ayさん: https://github.com/hayashi-ay/leetcode/pull/28/files 
+2回ループをどうにか1回ループで回せないか考えてみたが, 1回ループでまわしたあと, 辞書が順序を保存することを使わないとうまく書けないことと, 少し複雑な条件分岐が入ることを学んだ
+
+一応, 辞書を使っている人が多いのでdictを使うようにした。入力の文字列の名前がsなのでcharもcにした
+"""
+class Solution:
+    def firstUniqChar(self, s: str) -> int:
+        char_to_appear_count = defaultdict(int)
+        for c in s:
+            char_to_appear_count[c] += 1
+
+        for index, c in enumerate(s):
+            if char_to_appear_count[c] == 1:
+                return index
+        return -1
+
+# ループを一回に済ませる
+class Solution:
+    def firstUniqChar(self, s: str) -> int:
+        char_to_first_appear_index = defaultdict(int)
+        duplicated = set()
+        for index, c in enumerate(s):
+            if c in duplicated:
+                continue
+            if c in char_to_first_appear_index:
+                del char_to_first_appear_index[c]
+                duplicated.add(c)
+                continue
+            char_to_first_appear_index[c] = index
+        if not char_to_first_appear_index:
+            return -1
+        return next(iter(char_to_first_appear_index.values()))
\ No newline at end of file
diff --git a/arai60/first_unique_character_in_a_string/phase3.py b/arai60/first_unique_character_in_a_string/phase3.py
new file mode 100644
index 0000000..0c7c3a6
--- /dev/null
+++ b/arai60/first_unique_character_in_a_string/phase3.py
@@ -0,0 +1,10 @@
+class Solution:
+    def firstUniqChar(self, s: str) -> int:
+        char_to_appear_count = defaultdict(int)
+        for c in s:
+            char_to_appear_count[c] += 1
+            
+        for index, c in enumerate(s):
+            if char_to_appear_count[c] == 1:
+                return index
+        return -1
\ No newline at end of file