Birthday: April 30
Zodiac sign: Taurus
Blood type: 0
Height: 180 cm
Weight: 66 kg
Best subject: English
Worst subject: Art
Favorite food: Curry
Least favorite food: Liver
Favorite musician: Janis Joplin
Siblings: One younger brother
First love: 2nd year of middle school
Usual snack: Kari Kari Ume (crunchy plums)
Favorite beverage: Coke
Favorite color: Emerald green
Other: He can't wink.
Kou's older brother by eight years. He works as an English teacher at Futaba's high school. Futaba was initially interested in Youichi upon entering high school because he reminded her of Kou, but was unaware that the two were brothers. Youichi knows about Shuuko's crush on him but always rebuffs her advances, telling her that he will never see her as anything more than a student. However, he never hesitates to help her in times of need and is happy whenever he sees that she is fitting in. He enjoys a playful "rivalry" with Aya over Shuuko. He often gives Futaba advice whenever she feels unsure about herself or about Kou.