Kimi ni Straight

From the Animeraider:
Arashiyama Sagano just got beaned on the head by an errant baseball thrown by a rather rude calssmate named Awano. This was his method of finding a manager for the baseball team, for whom he pitches. Sagano reluctantly accepts and she becomes the team manager. Thing is, Awano's got game, much like his father who went to Koushien in his time. Is Sagano falling for him?

From Yacchan:
Sagano is the Baseball Club's manager. But the truth is, she doesn't really know anything about baseball. Awano, from the same class, forcibly convinces her to take on the role thinking that it will be easy. But that same Awano only bad-mouths Sagano. Even if his attitude is like that, will Sagano one day fall for him?

Volume 1 of Yabuuchi Yuu Masterpiece Collection:

1. Kimi ni Straight
2. Ojou-sama ni wa Kanawanai
3. Tonda Shinkiroku