Kujibiki Tokushou: Musou Hāremu ken - Chapter 100

Our straight (?) bottom woke up ten years into the future and found himself on the bed of his childhood friend… At the start, the bottom was shocked to his very bones, but he soon quickly accepted this premise and found the whole situation to be rather amusing. Precisely then, the bottom once again went back to his timeline — back to when he and the top were just platonic childhood friends.

The planet was invaded by the Tates, and suffered from the devastation of the last ages. In the crisis of survival, some humans awakened powers, and they realised that those mutant beasts could cooperate with their own consciousness and increase their fighting power to two times more.

This kind of animal was called Warpet. Shu Xiaohui was somewhat different from others. When the Tates invaded, he became a hamster and silently felt the presense of another powerful person.

Chen Chengduo watched his companions slowly find their warpet, and wondered where his one was until one day he saw Shu Xiaohui with his mouth full of melon seeds in the corner of the wall…

Others were warpet, his was only just a pet right…

Hamster: You… You don’t look at my small size. I have lucky BUFF!

- Description from Novelupdates

What is a young teacher to do when stuck with four cute little students in a beast apocalypse?. It's obvious, raise himself four little wives!!Well it's not his fault after all. They are the ones initiating it. As far as he's concerned, he's the victim of the story.“These four little devils, they are definitely after my back!”