Responses
there is kuroko no basuke, one of the characters (Kise) can copy abilities after seeing them but its not a volleyball manga. Its a basketball, so maybe its not what you are looking for ╥﹏╥
(even if it isn't, you should give it a try! there is an anime adaptation too and both works are AMAZING)
I need help find a manga its about volleyball (i think) basically there is a boy who can copy anyones ability after only having seen it once