Homare Onishima, Shion Kujou, Asuka Suzumori, and Mutsu Amatani are stuck on a lonely island when a school trip goes disastrously wrong. While Shion, Asuka, and Mutsu are terrified and frantic, Homare appears unusually calm. Fortunately for the rest of the gang, this isn't her first time being stuck! Homare spent her youth traveling across the world with her survivalist father, climbing cliffs, collecting wildlife, making shelters, and gaining critical nourishment from moose testicles. Surviving on a deserted island with a small likelihood of rescue is child's play for Homare. The only issue is with the other three.