Crossover Anime/Manga - Not Everyday Life

The minister is Yukino Yukinoshita.
My neighbor is Shiina Mahiru.
Her classmate is Yui Yuigahama.
The student council president is Kaguya Shinomiya.
The transfer student is a pair of quintuplets...
Xia Sheng has arrived in the world of anime, but something seems off about this world.
At night, he enters strange dreams, fighting monsters and gaining abilities—strength, charm, drawing, writing, music...
During the day, some people mutate, becoming like monsters and harming people; he wants to protect the world.
This is an ordinary world, but this world is not ordinary.