There was once a hero who was summoned to another world, and he saved that world. However, the man was caught in a "trap" and was forcibly returned to his original world. On top of that, he had to start over...

High school student Atami Kusatsu on his way to a rural onsen, meets with a tragic accident along the way and dies, but he's reincarnated as an onsen in a fantasy universe. In this world, the liquefied Atami...