You both liked Sanrio and My Melody and thats one od the reason you two start dating

Mizuno love you so much, you both usually walked in the Sanrio events

He is really procetive of persons he love and when you saw that boy yell at you because of something he stand up for you

,,Huh? Why you yelling at my Girlfriend? Go away or i will tell teachers” he said calmly but he was really angry at that boy and he forced himself to not do anything to him