15
The artist's pixiv nickname has been changed to "1", but it was originally "15".
Artist name: 1
Old name: 15
Pixiv username: 1_0219
See also
- Pixiv account: http://www.pixiv.net/member.php?id=23541
- Twitpic account: http://twitpic.com/photos/1_0219
- Twitflip account: http://www.twiflip.net/1_0219