My name is Sin and I am a custodian at a martial arts school! I know and remember thousands of techniques that became our heritage. My whole life is about preserving knowledge. I was reborn in a fractured world after destroying the school that was my home. This is someone else's world for me, someone else's life, someone else's body. But since I have a second chance, I will do everything to revive the Sword school here and make the whole world talk about it! After all, I am the keeper.