Minamission!

A tropical trio of lovely ladies undergoes survival training in the tropics! Three second-year high school girlsfrom a military academy—tomboy Kasumi Minami, ditzy airhead Raika Utsuri, and dependable Subaru Toma—are sent to survival training in Nonamimi, an uninhabited island in the southern seas. The girls find out that their wild tropical army life is fraught with all sorts of problems from day one! Will they be able to carry out their mission, and graduate in one piece?!

(Source: Manga Box)