Maruyu

"Nice to meet you... Maruyu, reporting for duty. Huh? You haven’t heard about it? ...Oh no...!"

The Type 3 submergence transport vehicle (三式潜航輸送艇 San-Shiki Senkō Yusōtei?) was a class of transport submarines of the Imperial Japanese Army (IJA), serving during the Second World War. The IJA planned to build over 400 boats, however only 38 boats were completed until the end of war. The IJA called them Maru Yu (マルゆ?).

Appearance
As a character, she has parted short black hair and brown eyes. She wears a white school swimsuit with a red encircled "yu" painted on her chest as well as a diving mask. Carries a transport container in left hand.

Personality
Historically, the Maru-Yu submarines were of a highly unusual design, and initial tests failed to get the prototype Maru-Yus to actually submerge, causing many Maru-Yu jokes to involve her only managing to get her head underwater while her legs still flail above water. Kiso was nearby in the test runs, and Kiso's crew made jokes about the Maru-Yu's strange shape, causing some artists to treat Kiso as some sort of sempai to Maru-Yu because of it.

Trivia

 * She is a very unique submarine because she was designed and operated by the Imperial Japanese Army.
 * She calls herself Maruyu. This comes from the circle "〇", which is read as "Maru", and the hiragana character "ゆ" which is read as "yu"(the first Japanese character for the word transport vehicle, her official classification). Also, the character ゆ inside the character 〇 resembles a fish in a fishbowl, fitting for a sub.
 * Adds luck when used as a material in modernization. The Kai version will add more luck.
 * She is the first ship in the game being a 艇(Tei) instead of 艦(Kan).
 * She is the first kanmusume in the game that represent a ship class instead of a single vessel. The formal name of these vessels is Type 3 submergence transport vehicle and as of the end of WWII, there were 38 of them completed.
 * She is the vessel with least displacement implemented into the game, and its length is just 47% longer than Type 2 Large-sized Flying Boat or 80% longer than Type A Kouhyouteki. So far, the second smallest implemented submarine in the game, U-511/Ro-500, is double Maruyu's length and triple Maruyu's displacement.
 * The freight tube carried by Maruyu in illustrations is in real life a tube-shaped powerless submarine designed by Imperial Japan Navy, and is dragged by other submarine, but never used by Maruyu in history due to it being an invention by Navy instead of Army and Maruyu is too small. The larger tube would be as long as a Maruyu.