404. That’s an error.
The requested URL /_/+1/confirm?hl=ja&url=https://miyavi.net/%E7%B2%BE%E6%B6%B2%E3%81%B8%E3%81%AE%E4%B8%8D%E5%BF%AB%E6%84%9F%E3%80%81%E8%A6%8B%E9%81%8E%E3%81%94%E3%81%95%E3%82%8C%E3%82%8B%E6%80%A7%E8%A2%AB%E5%AE%B3%E3%80%80%E7%BD%AE%E3%81%8D%E5%8E%BB.html
was not found on this server. That’s all we know.