Sankichi Hinodeya
From Inkipedia, the Splatoon wiki
Sankichi Hinodeya (ひのでや参吉 Hinodeya Sankichi) is the creator of the Splatoon manga who worked on Kanitama-Kun, Arincho-Kun, Mega Man, and The Dempa Men before being attached to the Splatoon characters so much that he had to work on the Splatoon manga more.