When he was a child, his parents made him attend a kid’s skating class, where he met Yukina who trained him. One day half a year later, he fell over her and accidently kissed her. Yukina got angry and started ignoring him, while Shizuka embarrassed would look away whenever they make eye contact. He received a letter from her, saying she’ll be waiting for him to give him a special training. However he could not come for he fell sick, and he learned a few days later that Yukina died in an accident, so he quit skating.
For 5 years, he would receive the same letter every year, since her spirit remained waiting for him at the local ice skating rink, so he consulted Rinne for help. Since Yukina did not recognize Shizuka for having grown up, a copy of his young self was used and after some difficulties she would skate with it, and so pass on. He admitted she was his first love.