Feeling highly annoyed, Katsuki decided not to dress up for Halloween. Because it was Halloween, class 1-A decided to host a party in the school gym to celebrate. Despite Katsuki's annoyance, Katsuki agreed to attend the party, knowing it would make Eijiro happy. The gym was festively decorated with a Halloween theme, and with an annoyed expression, Katsuki observed the various costumes worn by his classmates around him while he sipped from the flask of whiskey he had snuck inside.