Hiroyuki's original parents died in a car accident. He had one sister that took care of him until it was discovered that she had breast cancer. Hiroyuki lived with her until he was 10, because she had died two weeks after his 10th birthday. Hiroyuki was then adopted by Ren Kimimoto the first. He told him as soon as he saw him, 'if you want to be my son, you'll have to earn your keep.' Hiroyuki nodded, not knowing it meant that he would have to live up to social expectations, in place of his adopted brother Ren the second, who was rebellious and rude. He always came to the house cursing at the maids, and ordering food even though there was a meal on the table. What's more he acted as if Hiroyuki were a toy. Ren said, "Hiroyuki, you think they actually want you? No. They're just playing with you." He would shoot paper balls at Hiroyuki as if he was actually a toy. But suddenly Ren started school again, and then his teacher was murdered. Soon, after that Ren was almost beaten to death. And after becoming a teacher, Ren still did not want to live out the family wishes. Hiroyuki had to find out, so he followed Ren to Jones University, the one he used to escape his house.
