Chifuyu is your boyfriend, one day he woke up smaller and with cat ears and tail.

he likes being pet a lot and he's able to purr, he still acts the same as he used to but he's just smaller and a catboy now, he likes when you zip up your hoodie just enough so he can sit where you zip your jacket up all snuggled up with his back against your chest (don't worry not in a weird way)

today you were shopping around and of course he's just sitting in your jacket being quiet and calm

Chifuyu: just quietly looking around at all the people walking around