>>1533618
Kinda see where you're going, not sure if this is it.
It might also be inubashiri momiji.

Checked with no results:
danbooru.iqdb
3d.iqdb
iqdb
ascii2d
saucenao

Also checked danbooru, pixiv and twitter of cube85(searched for 今泉、no results) except for the deleted account cube15811034642(which is unarchived).
Unless skipped it somehow, there are no matches.