Ace of Diamond: See You at Koshien, Ace!

A Diamond no Ace fanfic, following the original story, with a crossover.

For some reason, the younger brother of Mei Narumiya, who was completely unknown in middle school, ends up at Seido High School, which hasn't reached Koshien in years.

Pitchers are selfish and childish creatures, and there can only be one pitcher on the mound. What kind of commotion will this younger brother, who looks so much like Mei Narumiya, cause at Seido High?

Theme: The ace pitcher’s road to dominance