Yuki's past has scarred him and he is constantly taunted with the images of his past and his sensei. Shuichi's presence has forced him to recall his past and force him to overcome the pains he's endured for six years.

There is a reason behind Yuki's stubborn and harsh personality. He's known to give death glares to people he's not fond of, and Tachi Aikawa, a member of the band ASK, once claimed that he has the eyes of a killer. Taking that into consideration, his thought is terribly ironic. You see, Yuki's looks do not resemble those of a Japanese person, and because of that, he was taken to New York to live for a while. It was there that he met Kitazawa Yuki, a cute and seemingly loving young man that Eiri-san soon fell in love with. In a way, Kitazawa Yuki and Eiri-san are a lot like Eiri-san and Shuichi. Back in New York, Eiri-san was a very cheerful and genki little boy, much like Shuichi. He was always running around looking for Kitazawa, his tutor and friend. Kitazawa was more mature and collected. However, Kitazawa has a drinking disorder, and when he's drunk, his personality totally changes from a loveable young man to a uncontrollable fiend. Each time he got drunk, his behavior became worse. It was because of his drinking behavior that caused him to hire men to sexually abuse Yuki for a cheap amount of 10 dollars. The poor sixteen year old boy was indeed very frightened. Yuki ended up killing Kitazawa by shooting him with a gun. Tohma found Yuki just after the shooting and attempted to comfort him by saying that it wasn't his fault...

But that wasn't much help, because the deed was done and Kitazawa was dead. Tohma made sure Yuki wasn't convicted, and Yuki was shaken and forced to endure the pain, thus enabling him to become isolated from those he close to him. Yuki came to Japan and started his life over as a writer. He took on Kitazawa's pen name as his own. He truely cared for Kitazawa and killing him was probably the last thing Yuki wanted to do. Therefore, Yuki wanted to forget what happened and supress his feelings. He was slowly forgetting and enduring until Shuichi came along. Shuichi's uncanny resemblance to Yuki's younger self forced Yuki to recollect his past. His condition became worse and his doctor prescribed a stronger tranquilizer for him to help the pain. However Yuki later threw up blood while talking to Tohma, and was hospitalized. In the end though, he tore up the picture of himself and Kitazawa and threw it into the sea. He visited Kitazawa's tomb stone and then went home to Shuichi.