Jinmen

Jinmen (ジンメン) is a manga written and illustrated by Takahiro Katou. It is serialized in Sunday Webry.

Plot
After a few years, Jinguu Masato, returns home. Due to his nature, he loves animals and he also likes to visit them. Because of this, he loved to visit the zoo since he was small and that's how he developed a close relationship with Hanayo. However, Masato gradually starts to notice some strange incidents happening in the zoo and after that, he's thrown into this unexpected world..