Winter break. A series of graffiti incidents occurring all over the city prompts a request for backup to Endeavor's agency, where Deku, Bakugo, and Todoroki are interning. The culprit is a man who calls himself Mr. Smiley and claims to be an artist. Thanks to his "Quirk," even the police have been struggling to apprehend him. Endeavor initially dismisses the case, saying, "Such petty crimes should be handled by the police!" However, when graffiti appears on the wall of his own home, his attitude changes completely, and he sets out to make an arrest. But Mr. Smiley proves to be a far more formidable opponent than expected—!