Add a picture to the 写真 on your プロフィール page. Once あなた do, click on the 写真 button on your プロフィール page, and look for the picture that あなた want. Once あなた find it, you'll see a small button that looks like a person. Click on that person and you'll have your プロフィール picture. As for background, this only works on クラブ you've created. あなた need to click on the 編集 button, and go the Banner option, and select a picture to the ones あなた have saved and アップロード it to the banner. This also works for the クラブ プロフィール picture as well, only smaller. I hope this all helps
