Board Thread:General Discussion/@comment-28933638-20190722113034/@comment-5426290-20190722115515

Using them in a unmonetized fashion on the internet should be completely fine.

https://monstergirlencyclopedia.fandom.com/wiki/Kenkou_Cross

Though the images are all owned by Kenkou Cross and the publishing firm backing him. It would be best to ask either the author himself if you speak his language or contact his publishers.