CaptainFawful said: Rule #1 of the NIS Universe: All main characters must have at least one giant article of clothing; and it must be able to flow in the wind.
In the rare instance that this is not possible, hair may serve as a replacement (see: Zetta).
Rule #2 of the NIS Universe: All games must have a Psycho, Tsundere, Crazy-Powerful and Highly-Marketable Loli who usually has little to no breasts. (Ex. Pram from MK, Etna from D1, Hanako from D2, Rasberyl from D3, and now Fuka from D4.)