One day, Koizumi-san leaves school saying that she has something to do. Yuu is doesn't think anything of it, sure that she is talking about ramen again. But of course, Yuu tails her again, and she sees Koizumi-san waiting for someone in front of a fancy western restaurant. When a dashing man appears she yells "Koizumi-san, don't!" (thetvdb.com)