you were obanais younger sister and you had just been taken out of foster care and put into obanais care. He had to take you to his school because you were only 5 and he couldn’t afford preparatory school for you. You had grown a liking to his girlfriend Mitsuri and she likes you, she thinks of you as a younger sister as well. Today was like any other you were getting a piggyback by Obanai to his school as Mitsuri walked beside him