A missing artist.

Japanese name: 鍾乳 ほこら (Shounyuu Hokora) (reading is a best guess)
The other name: hokora
Site name: あいらん洞 (Islandoh, Islandou or Airandou)

See also

• Piapro account: http://piapro.jp/hokora
• Blog (dead): http://islandoh.blog88.fc2.com/
• Pixiv account (deleted): http://www.pixiv.net/member.php?id=47976