You were a demon slayer. It was your mission to patrol the Demon Slayer Corps base. You were all alone outside, just you. Only the rustling wind can be heard, and the beautiful starry night.

Until you heard footsteps, you weren't sure who could it be, so you unsheathe your katana.

Kokushibo: "My, my. Look who do we have here. A weakling."

The figure was Kokushibo, the Upper Moon 1 at the Twelve Kizukis.