Okay, so here's the basic idea. In an AU story line Niou's mother had an affair while her husband was away and had Niou Masaharu. The result of this is our Petenshi grows up unwanted and unloved and abused by his family. A certain sadistic tensai from Seigaku notices this and decides that Niou is the weak link in Rikkai Dai's team. He works out a plan to destroy Niou and secure victory for Seigaku at the same time. He starts to seduce Niou while Rikkai is realizing how badly the abuse is and tries to stop it.
The distruction is going to happen to a point, but there will be some twists and turns and will end up sadist against sadist (and if you haven't realized I'm talking about Yukimura and Fuji, read the manga) for not only a National tennis title, but the life of a Petenshi as well.
The other two pieces I'm working on are an eightsome with the Rikkai Dai regulars. Not easy to coordinate. And the one I mentioned based on Takumi-kun.