diff --git a/Qpid/handler/icons.go b/Qpid/handler/icons.go
index 0fe2631..437a96d 100644
--- a/Qpid/handler/icons.go
+++ b/Qpid/handler/icons.go
@@ -1,18 +1,86 @@
 package handler
 
-import "github.com/labstack/echo/v5"
+import (
+	"io"
+	"net/http"
+
+	"github.com/labstack/echo/v5"
+	"github.com/traP-jp/hackathon26spring_05/Qpid/domain"
+	"github.com/traP-jp/hackathon26spring_05/Qpid/handler/middleware"
+)
 
 // PATCH /api/me/icon
 func (h *handler) updateMyIcon(c *echo.Context) error {
-	return notImplemented(c)
+	username := middleware.GetUsername(c)
+
+	//ユーザー認証
+	if username == nil {
+		return unauthorized(c)
+	}
+
+	file, err := (*c).FormFile("icon")
+	if err != nil {
+		return c.JSON(http.StatusBadRequest, errorResponse{Message: "icon file is required"})
+	}
+
+	src, err := file.Open()
+	if err != nil {
+		return c.JSON(http.StatusBadRequest, errorResponse{Message: "cannot open icon file"})
+
+	}
+	defer src.Close()
+
+	blob, err := io.ReadAll(src)
+	if err != nil {
+		return c.JSON(http.StatusInternalServerError, errorResponse{Message: "failed to load user"})
+	}
+
+	mimeType := domain.IconMimeType(http.DetectContentType(blob))
+	if !isAllowedIconMimeType(mimeType) {
+		return c.JSON(http.StatusBadRequest, errorResponse{Message: "unsupported icon mime type"})
+	}
+
+	if err := h.repository.SaveIcon(*username, domain.Icon{
+		Blob:     blob,
+		MimeType: mimeType,
+	}); err != nil {
+		return c.JSON(http.StatusInternalServerError, errorResponse{Message: "failed to save icon"})
+	}
+
+	return (*c).NoContent(http.StatusNoContent)
 }
 
 // DELETE /api/me/icon
 func (h *handler) deleteMyIcon(c *echo.Context) error {
-	return notImplemented(c)
+	username := middleware.GetUsername(c)
+	if username == nil {
+		return unauthorized(c)
+	}
+
+	if err := h.repository.DeleteIcon(*username); err != nil {
+		return c.JSON(http.StatusInternalServerError, errorResponse{Message: "failed to delete icon"})
+	}
+
+	return (*c).NoContent(http.StatusNoContent)
 }
 
 // GET /api/users/:id/icon
 func (h *handler) getUserIcon(c *echo.Context) error {
-	return notImplemented(c)
+	username := (*c).Param("id")
+
+	icon, err := h.repository.FindIconByUsername(username)
+	if err != nil {
+		return c.JSON(http.StatusInternalServerError, errorResponse{Message: "failed to load user"})
+	}
+	if icon == nil {
+		return notFound(c)
+	}
+
+	return (*c).Blob(http.StatusOK, string(icon.MimeType), icon.Blob)
+}
+
+func isAllowedIconMimeType(mimeType domain.IconMimeType) bool {
+	return mimeType == domain.IconMimeTypePNG ||
+		mimeType == domain.IconMimeTypeJPEG ||
+		mimeType == domain.IconMimeTypeWebp
 }
diff --git a/Qpid/infrastructure/icon_repository.go b/Qpid/infrastructure/icon_repository.go
index 3982d42..28510bb 100644
--- a/Qpid/infrastructure/icon_repository.go
+++ b/Qpid/infrastructure/icon_repository.go
@@ -1,6 +1,7 @@
 package infrastructure
 
 import (
+	"database/sql"
 	"errors"
 
 	"github.com/traP-jp/hackathon26spring_05/Qpid/domain"
@@ -48,7 +49,11 @@ func (r *repositoryImpl) FindIconByUsername(username string) (*domain.Icon, erro
 		"SELECT icon, mime_type FROM icons WHERE username = ? LIMIT 1",
 		username,
 	)
+
 	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, nil
+		}
 		return nil, err
 	}