The protagonist Shinko Inoda enjoyed his routine even though he was tangled up by his close-knit heterosexual friends.
At that time, a magic formation suddenly appeared in the classroom and they were transferred to Eldias, another world. From there, he was driven into a battle to save the country. Some friends of the opposite sex could rely on Shinkan even if they moved to different worlds, but didn't feel comfortable about it. Shinko was assassinated shortly after the final showdown by the man. When
Shinkan woke up again, his body was red. And I realized that I had been reincarnated into the son of the demon king.