okay so itafushi baseball au:
I saw art of this too and became OBSESSED. I grew up in a baseball household, like baseball is on literally all year round, my bedtime stories were baseball stories, my dad has about 100 baseball books including encyclopedias and shoeboxes full of baseball cards, so I know waayyyy too much about this sport.
The rivalry ideas you had for the nobamaki basketball au is actually closer to what I have for the baseball au.
So, Megumi is a pitcher, Yuuji is a catcher. Right? Right. So, they start on different teams, either they're on rival teams in middle school, or Yuuji starts at a different high school, I'm not sure. But either way, they develop a rivalry. Yuuji is a pretty good hitter, a slugger mostly so he hits a lot of home runs, but he's really fast too so when he gets on base he's dangerous. Megumi is this super gifted starting pitcher. He keeps perfecting new pitches to the point where in high school he's got 4 or 5 pitches he can throw reliably, so batters never know what's coming (for reference, in the majors most starting pitchers have 3). He's a decent hitter not amazing, but his on base percentage is huge. Partially because he's really good at reading the pitcher and is good at drawing walks, but also because he crowds the plate and gets hit by pitches, like A LOT. My self-sacrificial king.
But basically, when they're on different teams Megumi, the super gifted pitcher, is pitching to Yuuji, the home run hitter. So a huge challenge for both of them. and Megumi gets *pissed* anytime Yuuji gets a hit off of him. And when Megumi is hitting, Yuuji is behind the plate shit talking and trying to psych him out. Perfect antagonistic rival dynamic haha.
But then, when they end up on the same team suddenly they're the most important duo on the field and they have to learn to work together. Do you see my vision? Do you see it???
And yes, absolutely, with Megumi pissing off opposing pitchers by standing over the plate he's gonna get thrown at. Clocked in the face can be pretty serious lol but my dude loves to get his shit rocked so I won't rule it out. And it absolutely pisses of his coach (Gojo, obvi) that he taunts the pitchers so much, cause a pitcher getting hit in the elbow or something can ruin their season if not their career. But he's gonna do it if he can automatically advance a runner to second by getting a walk.
Sorry for not replying earlier ! (was super busy yesterday). I’m gonna be honest I don’t know shit about baseball but I DO your vision. If hours upon hours of watching and reading about baseball is what it takes for this au to flourish, then I will spend hours upon hours watching and reading about baseball. I love this