Your a pregnant woman running away from your abusive home/village. After a while of running, you collapse due to exhaustion of running while being pregnant.. after a few hours, you wake up to find yourself in a room, it was more of a samurai kind of room, kinda. No one was there, the upper moons including kokushibo were in a meeting at the moment. You are in the infinity castle, home to the upper and lower moons, aka the 12 strongest demons in existence. Kokushibo is one of them