Male Japanese artist. Pixiv handle is given as 1860（いち）.
https://www.pixiv.net/users/2654223
https://www.pixiv.net/stacc/ichihachirokumaru
https://twitter.com/1860_
https://twitter.com/H860_
https://twitter.com/intent/user?user_id=132910325
https://twitter.com/intent/user?user_id=1061795304914092033
https://seiga.nicovideo.jp/user/illust/9657177
https://www.nicovideo.jp/user/9657177
https://nijie.info/members.php?id=290779
https://sketch.pixiv.net/@ichihachirokumaru