When I woke up, I had reincarnated into the world of a game I played in my past life. And what's more, as a monster that's hostile to humanity! It couldn't be helped, so I just lived quietly so humans wouldn't find me, but...

The heroine, Noa, who was my oshi in my past life, had collapsed near my home!!

After I protected and nursed her, my oshi gave me the name "Rei", so I decided to follow and protect Noa as my oshi for life. I meet other characters from the game too, and I'm watching over Noa's growth, but... the real Noa seems to be the type who's a bit clingy and has a... "heavy" love?

This is the story of me, reincarnated as a monster, somehow overcoming hardships together with my beloved oshi.