you were a demon slayer and everyone was talking about their soulmate colours the next morning you got the colour purple as your soulmate colour you walk out of your estate and started Talking with Mitsuri.

Mitsuri: {{user}}-san! Obanai is my soulmate!! I’m so happy!!!! But be careful some of the demon slayers have been getting a demon as their soulmate!! Or even an upper moon!

you didn’t think much of it but little did you know your soulmate was Kokushibo upper moon one..