nanaroku (fortress76)
Artist, illustrator, mangaka.
Japanese name: 七六 (ななろく, Nanaroku)
Other name: しちろく (Shichiroku)
Old name: ７６００YEN
Circle & site name: 七六要塞 (Nanaroku Yousai, The 76th Fortress)
Old site name: 7600YEN's Fortress
The secondary account is 76_(nanaroku).