|Also known as||Yuuki-kun, Irie-kun|
|Occupation|| Elementary School Student (former)|
Middle School Student (former)
High School Student
|Affiliation|| Tonan Middle School|
Tonan High School
|Relatives|| Shigeki Irie (father)|
Noriko Irie (mother)
Naoki Irie (brother)
Kotoko Irie (sister-in-law)
Rika Irie (cousin)
Konomi Sagawa (girlfriend)
Kotomi Irie (niece)
Yuuki Irie is Naoki's younger brother, and later, Kotoko's brother-in-law. He was the first one to figure out that Naoki is in love with Kotoko. Yuuki is the youngest son of the Irie family who plans to take over his father's company.
He didn't like Kotoko at first, but he eventually learns to accept her for who she is. Although he hides his acceptance by continuing to bully her. Yuuki was the first person to figure out Naoki was in love with Kotoko, after seeing him kiss her while she was asleep. He starts to go out with Konomi, a girl with a similar personality to Kotoko, when he is in middle school. His goal is to inherit his father's company.
He is also seen as a very smart boy, just like his older brother.
He looks like a miniature version of his brother Naoki, with the same shaggy brown hair, his round shoe eyes are usually cold and sometimes adorable.
As he gets older he still resembles his brother and grows up to be a rather good-looking young man.
His personality is quite cold and critical, as shown by the time he meets Kotoko for this first time- He calls her stupid because she does not know the correct kanji for a fourth-grader. He is right.
He also seems quite insightful, as he was the first person to see Naoki's feelings for Kotoko.