|“||...I do adore him. I love him and want to protect him. If he's in pain, I want to make whatever's hurting him go away. It's probably never occurred to you... but there exists a kind of love...that dangerously close to hate.||”|
He is also the only Zweilt that Yuki seemed to have a strong recollection of despite his memory seal, calling him "Asagi," (His former name) before Sairi had even introduced himself.
Sairi has medium-length platinum blond hair which is parted to the right and the golden eyes of the Giou line. He is said to be incredibly handsome, so much so that every time he got a job, he would always be fired within the month due to getting into fights with guys who claimed that he stole their girlfriends.
He also holds the "Eye of God," though it is considerably different from Shusei's as his are often called "Malicious Eyes," as he can do suggestions and manipulations using his eyes.
He is a freshman in college and goes to the same college as Senshirou. Tsukomo politely notes him to be a "chivalrous man," while Hotsuma more bluntly calls him a "smart-ass and a womaniser." He does not get along with Hotsuma and Kuroto and argues with them quite frequently.
He is one of the most mysterious characters in the series and seems to have a secret involving Yuki that no one else knows. When he first saw Yuki again he remarked that it was painful seeing him again. Luka seems to not trust him around Yuki and asks if he had done anything to him.
When alone with Yuki his personality changes between being cold and distant or gentle and caring. When Yuki confronts him about avoiding him, Sairi explains that it was not his intention, as he is only confused on how to treat him. 
Luka would later tell Yuki to stop thinking about Sairi because he won’t be able to understand him no matter how hard he tries and it’ll hurt. Yuki asks if something happened between Sairi and himself in the previous life but Luka stays quiet. Yuki knows that the Zweilts can’t hate him, but he feels as if Sairi does.
Sairi remarks on how the fact Yuki changed gender was probably his fault. 
When Ria and Touko are talking in story 41, Ria tells Touko that she didn't like Sairi until she came to know his secret that completely changed her view of him.
Sairi admitted that he did adore Yuki just as the other Zweilts, but told Masamune that his was a type of love that is dangerously close to hate. 
- "The task to protect Yuki was given to you, and you returned here on your own. If it were me, I would have never left his side."
- "During those days when death was just around the corner, circling us, her existence alone was our peace and happiness, our light -- Why then was I only able to stand by and watch, without being able to do anything?"
- "I want the moon, up there. But...he will always be unreachable..." (Referencing Yuki's former name, Yuuzuki, which has the character (月 ) "moon."
- "The fact that you changed your gender when you were reborn...I wonder if...it's my fault after all?"
- "I just can't leave him alone. I want to protect him."
- Asagi was his name in a previous life.
- He has a brother who died but nothing was revealed more than that. Though it seems as though his brother was Ria's former partner.
- Due to the fact that he grew up without a mother, he is quite proficient at cooking