oh btw just to explain what cosplay is, basically it's crossdressing as a fictional characters from games, animes, mangas and sort of things. there are plenty of people who do it either for fun or for money.
manga - a comic book but please do not mistake it with other well known comics. mangas have very high variety of types there is probably more manga types than book types, its read down from 10 year old kids up to no age borders ive seen many pics of old japanese ppl reading a manga or stuff.
anime- animated movie. most of them are just animated versions of mangas and again there is much more anime variety than typical non animated movies you can go up from silly animes for little kids up to very psychological ones really there is no boundaries in anime types.
Ah the pic of green haired girl above is actually a cosplay of fictional character Hatsune Miku a "vocaloid" which basically means a personalized software that... sings, yup you read it correctly. Bunch of guys started to create a software that can sing whatever lyrics you put it to use.