That Time I Got Transmigrated into Tensura

Runin was a rather humble young man. He always did all his homework, respected his elders, helped the needy; and never! Ever! Cheated on his girlfriend.

Sadly, his obsessive girlfriend—uhm ‘wife’—didn't think so, leading to a very pleasurable death.

The next time he regains consciousness, he finds himself in a very precarious situation.