hitsuji_bako
Artist whose nickaname is the same as his cicrle name.
Nickname & circle name: 羊箱 (Hitsuji Bako, lit. Sheepbox)
The artist said "the reading is 'Hitsuji Bako.' However, everyone calls me 'Youbako.' For sure, it's easier to pronounce. So that's also okay."
Site name: しーぷぼっくす (Sheepbox)