Once Kirumi and Celestia ambushed Kokichi and dressed him up in a Victorian dress with lots of frills and took him to one of their tea parties.
But surprisingly he kind of enjoyed it so they now regularly kidnap him and put him in ridiculous dresses.
Bonus:
He gets super giddy and giggly when all dressed up. So the first time Shuichi saw him in a dress he started madly blushing and asking what was happening. Kokichi just started half-lying and got even gigglier than normal and had to be dragged away by Celestia and Kirumi.
