Ookiku Furikabutte: Natsu no Taikai-hen

sports anime, introvert protagonist and all those excitements any sports anime would provide. 

Its a boxing anime but similar this anime is about a boy that went from being bullied everyday to becoming one of best boxers. 

I watched both anime and both have almost similar traits in almost all aspects of baseball , except the them , where Ookiku focused tends to realistic-friendship wise , and Daiya no ace more to individuals term. However , if you like Daiya No Ace , I am sure you would also interested in Ookiku Natsu N.T.H.(theres a prequel too)  

Both the protagonists are similar in terms of thinking that they are useless and is only good in one thing. Both shows reveal the analysis of both sports involved, which is cycling and baseball. 

They are similar in that way both are about sport in high school and that the main charter grows alot on a personal level and gets better at the sport they are playing! so if you like Eyeshield 21 then i think you would like Ookiku Furikabutte aswell!