Kawashima, the school nurse, has to go to a training camp just when her son, Yuta, comes over to see his mother. Because she can't cancel the training camp, Yankumi invites Yuta over for the night and until Kawashima came back, Yankumi has Yuta over to her classroom. They didn't know that Yuta didn't inform his granparents, that he's visiting Kawashima and that Yuta isn't actually related to Kawashima by blood. Refusing to give up, Yuta runs away and everyone hurries to find him.