One day, I became immortal...

Sudou Masaki, a struggling picture book author, disappears without a trace after being caught in a major earthquake one day. When he awakens, he finds himself in another world. That alone would have been a major problem, but he was even more confused by something else. It was because his body had been enhanced to an incredible degree. In this unfamiliar otherworld, he travels from place to place and gets caught up in various disturbances. Each time, he resolves the problems with his characteristic (?) invincibility. "Why do I have this kind of power?" Wondering this, Masaki continues to get caught up in the turmoil of the otherworld today as well.