Shikotama, an ecchi sports manga by Jun Nishikawa, ran in Bessatsu Shonen Champion in 3 volumes from 2012. There are two other manga also called Shikotama, but this one is about fanservice+baseball so don’t confuse them. This is the one I’m talking about: Shikotama on Mangaupdates. Ignore the nonsensical description over there.
Shikotama is about a girl named Tama who is a phenomenal pitcher (in name only. She’s not really all that good). She enrolls in a famous sports academy with the hopes of becoming their ace pitcher only to be told that girls can’t play with boys at the high school level. Interestingly enough it seems they can play with boys at the grade, middle school and college levels, though I’ve never actually seen a girl playing baseball at the college level with boys
She talks the boys on the team into giving her a pitching test, which she fails, but when she plays the “It’s because I’m a girl, isn’t it?!” card and they give her another challenge: form your own team and play against us. The winning team becomes the official school team. Thus Tama sets out to get people together, starting with a girl named Shiko, who has trained all her life to be a sumo wrestler. Shiko (catcher) + Tama (pitcher) = Shikotama.
I wish I could tell you how the manga ended, but I stopped reading after chapter 3 so I wouldn’t know. Since Shikotama is only 3 volumes long, it’s quite likely that the girls’ team failed to beat the regulars and continued playing normally, but I’m just guessing here. Like most manga about girls’ baseball, Shikotama is going to spend a lot of time first getting the team together before anything of note happens. There isn’t much sports action to be found in the earlier volumes, at any rate, apart from one pitch or one at-bat challenges.
The real reason I quit though, was because it’s a sports comedy manga that isn’t very sporty and isn’t very funny. It tries to make up for that lack with a truly ridiculous amount of fanservice, which is fine if you’re into that sort of thing but I’m not. If anything it makes Tama look even less talented than she already is when she resorts to showing off her bra and panties in every single game.
If you distract a world-class batter with your goods and manage to get a single strike against him, that does not make you a pitching genius. I’m not discounting the possibility that there might be female pitchers out there as good as male ones at the high school levels, but Shiko and Tama’s shenanigans and excessive fanservice only make them look desperate and inferior. It’s like Princess Nine all over again.
If you like fanservice, though, you might enjoy yourself. As a sumo wrestler big-busted Shiko wrestles takes on the whole sumo team dressed in only a skimpy loincloth and a few strategically-placed strands of hair. Then at the start of chapter 4 she wins a bet that lets her decide what the rest of the team will wear as training uniforms and chooses loincloths… Yup. I stopped reading at that point because it exceeded my acceptable levels of ecchiness. Shikotama is for fans of excessive fanservice and borderline nudity only.