Takaya Mizushima (水嶋貴也 Mizushima Takaya): He is a classmate and friend of Hiroko and Shiina. He has a crush on Shiina and has two older sisters who constantly tease him about it. He is the first one to realize Hiroko's strange behavior, but does not know that it is due to the bullying. After coming across Aki Honda and her group of bullies raping Hiroko with a test tube, he yells at the bullies to stop and drives them away. Then, Mizushima travels to Hiroko's house and tells her that he will protect her from her troubles; Hiro tells him that it is "too late," but he is not killed by Hiroko's dragon due to his kindness. Later attending a coeducational junior high school, he appears sporadically throughout the rest of the series.
His Japanese voice actor is Hikaru Tokita.