TV-Series
Description
Kaoru Yui is a first-year student at Seidou High School who joins the baseball team as a catcher. He wears jersey number nineteen for the summer tournament and is also noted for his ability to play as an outfielder. Yui has a small physical stature, light brown hair, thick eyebrows, and large eyes, often appearing with a characteristic smirk.

Before attending Seidou, Yui was the unshakable starting catcher for the Mamiya Senior League and gained recognition as a child prodigy, having captained the Japanese representative team in the Little League World Series. His motivation for joining Seidou was to catch the pitches of Satoru Furuya, for whom he has a deep respect, and to learn from the skilled catcher Kazuya Miyuki.

Yui possesses a highly competitive spirit and hates to lose to his teammates, whether in running laps, batting practice, or even eating meals. He demonstrates resilience and a strong work ethic, consistently volunteering to catch for pitchers like Satoru Furuya and Eijun Sawamura. He views the challenge of catching difficult pitches as an opportunity to prove his worth, and when he is rejected, he channels his resulting frustration into motivation for self-improvement. Yui is also intensely self-critical, analyzing his performances and internalizing setbacks.

Yui's most notable role in the story is as a versatile player dedicated to the team's success. He displays a team-first mentality by readily accepting roles as a pinch hitter or left fielder. His abilities include impressive batting power that allows him to hit for long distances despite his small size, solid running speed, and a strong throwing arm. His stamina is also noteworthy, helping him keep pace with older teammates during rigorous training.

Regarding his key relationships, Yui is roommates with Satoru Furuya and Hiroshi Ono. He eagerly wants to catch Furuya's pitches and is interested in seeing them up close. However, he initially struggles with catching Furuya's powerful throws. He also expresses interest in Eijun Sawamura's pitches, finding them difficult to catch during their first bullpen session but remaining determined to succeed. A professional rivalry exists with fellow first-year catcher Koushuu Okumura, as both compete for playing opportunities.

Developments in Yui's character include his promotion to the first string during the spring tournament, where he observed Miyuki's leadership. Frustration from being turned down by pitchers pushes him to refine his skills. Later, he contributes to the team as a pinch hitter in critical games, such as the semifinals against Ichidaisan High, solidifying his role as a utility player for Seidou.