Kugane Maruyama

A young man is trapped within a video game as a warrior king, and sets out to make this new world his own empire.

The protagonists and other charactes of four anime series—"Re:Zero kara Hajimeru Isekai Seikatsu", "Kono Subarashii Sekai ni Shukufuku wo!", "Overlord" and "Y?jo Senki"—in where they are transported each one magically to another world are all summoned—in different and comical ways—to a High School, there, they are forced to complete a whole "school year " in order to travel again to their respective worlds. This is a "chibi" parody and all the characters interact between them in such a way.

Momonga, now known as the Sorcerer King Ains Ooal Gown, rallies the Sorcerer Kingdom and its undead army to join the fight alongside the Sacred Kingdom and the Slane Theocracy in hopes to defeat the Demon Emperor Jaldabaoth.