>>2714364From a meta perspective, being so popular for 3 years has allowed KanColle to attract a lot of artists due to the consistent large market as opposed to animes of the week which quickly wane in popularity as soon as they finish airing.
As for the girls themselves, school uniforms and zettai ryouiki. For me a lot of it is about their personality, but I don't know how much of that is apparent in the images if you don't know much about KanColle.
