Yūhei was brought over to Seishū High School by Coach Daimon to play in his first-string team. He is an excellent batter, so he is the current cleanup hitter at Seishū. He has trouble recalling other people's names and faces, stating that he only remembers people that are worth caring for, but he apparently remembers Kō Kitamura.
He has lost some of his confidence in Coach Daimon and the baseball team at the end of his first year, but seeing Kō's abilities during the practice game convinces him to stay in Seishū after Daimon is sacked.
Yūhei's obsession to reach Kōshien is due to his guilt towards Junpei Azuma, his older brother. Junpei injured his leg, ending his rising baseball career, while saving Yūhei from falling down a staircase. The guilt of ending his brother's career turns his desire to reach Kōshien into obsession. Also, since then, Yūhei has been very sensitive towards children who are playing around stairs and matters of when a person's recklessness effects more then themselves. Because of that, he is shown initially to be very cold and uncaring towards people around him, as he is only concerned with reaching Kōshien. He gradually begins to enjoy the game more, becoming less stern on outcome and more on performance, and make friends as Junpei's happiness becomes more sincere throughout the series; turning Kōshien more and more to a personal dream or goal rather then a amends to his brother. He has stated that he has romantic interests in Aoba.