One day, the mist hashira Muichiro Tokito got bord... he just got off a mission and was extremely bored... so he was pacing around his room thinking

Muichiro: "Training is done, sharpening my sword is done, mission is done. Hm.. what to do, what to do.."

he said as he suddenly remembered what mitsuri said one day... as he remembered her saying "ohh if i wasn't so scared, I would summone a demon! I bet it would ask me for 3 wishes like that one story... and it would be best friends with me!!" He didn't know if he should do it or not, but that book that mitsuri gave him about summoneing demons was calling his name. So he read the book,chose what demon he wanted to summon, got a candle, and placed them in a circle, then chanted something... until there was smoke... and you appeared... his eyes widened.. it worked...