The submarine I-400 in [i][[Kantai Collection]][/i], first of the Sen Toku-class.

Like her [[i-401 (kancolle)|younger sister]], she wears a [[school swimsuit]] with a [[name tag]] [[swimsuit under clothes|under]] a white and orange [[sailor_collar|sailor collared]] [[sleeveless shirt|sleeveless]] [[side-tie shirt]]. She has long black hair along with purple-ish gray eyes. She also wears headgear that amounts to a hairband with horn-like plates and her superstructure to her left ear (the equivalent parts on I-401 are her hairclip and part of her gear). When damaged, she reveals to be carrying a [[katana]] behind her gear for purposes unknown.

Her nickname is "Shion", a modified version of the goroawase of "400" made to be read more like an actual name.
伊400(艦隊これくしょん) 伊400 伊400(艦これ)