On Japanese wiki I believe that you can unblock yourself on this page: https://ja-knowpedia.myht.org/index.php?title=%E7%89%B9%E5%88%A5:%E3%83%96%E3%83%AD%E3%83%83%E3%82%AF%E8%A7%A3%E9%99%A4/Msnhinet8