diff --git a/components/AppContainer.tsx b/components/AppContainer.tsx
index 8c98254..8749908 100644
--- a/components/AppContainer.tsx
+++ b/components/AppContainer.tsx
@@ -18,7 +18,7 @@ import RefreshListsButton from "./RefreshListsButton";
 import CheckDoneButton from "./CheckDoneButton";
 import { useNowAllFollowers } from "@/lib/accessTwitch";
 import { debugLogger } from "@/lib/debugLogger";
-import { lastCheckedDateKey } from "@/lib/constants";
+import { lastCheckedDateKey, storedAllFollowersKey } from "@/lib/constants";
 
 export default function AppContainer() {
   debugLogger("AppContainer");
@@ -105,7 +105,10 @@ export default function AppContainer() {
 
   useEffect(() => {
     debugLogger("onChecked();");
-    if (!localStorage.getItem(lastCheckedDateKey)) {
+    if (
+      !localStorage.getItem(lastCheckedDateKey) &&
+      localStorage.getItem(storedAllFollowersKey)
+    ) {
       onChecked();
     }
   }, [onChecked]);
diff --git a/lib/accessTwitch.ts b/lib/accessTwitch.ts
index 62b25c8..eddb59a 100644
--- a/lib/accessTwitch.ts
+++ b/lib/accessTwitch.ts
@@ -110,10 +110,16 @@ export const useNowAllFollowers = () => {
     const resJson = await res.json();
     const followers = await fetchFollowers(resJson.data[0].id);
 
+    if (!localStorage.getItem(storedAllFollowersKey)) {
+      // addedUsers の差分が全てのユーザーにならないように、初期値はfollowers
+      localStorage.setItem(storedAllFollowersKey, JSON.stringify(followers));
+    }
+
     const result = await findDifference(
       followers,
-      JSON.parse(localStorage.getItem(storedAllFollowersKey) ?? "[]")
+      JSON.parse(localStorage.getItem(storedAllFollowersKey) as string)
     );
+
     debugLogger(result.removedUsers);
     debugLogger(result.addedUsers);
     setNowAllFollowers(followers);
diff --git a/lib/debugLogger.ts b/lib/debugLogger.ts
index ed1a184..2750f60 100644
--- a/lib/debugLogger.ts
+++ b/lib/debugLogger.ts
@@ -1,7 +1,10 @@
 const isDebugMode = (): boolean => {
   if (typeof window !== "undefined") {
     // Make it server-side compatible.
-    return window.location.hash.includes("debug");
+    return (
+      window.location.hash.includes("debug") ||
+      window.location.hostname === "localhost"
+    );
   }
   return false;
 };