Storyline
After years without seeing each other, the protagonist is unexpectedly invited on a summer vacation by their childhood friend, Mitsuki Nanami. What begins as a simple trip quickly turns into a fight for survival when their ship is caught in a powerful storm and the two are stranded on a remote island.
With civilization far away, they must learn to survive together. Food and water have to be secured, materials gathered, and tools crafted while they search the island for everything they need. A small shelter becomes their temporary home as they gradually improve their survival skills and uncover new ways to make life on the island easier.
As the days pass, the hardships of island life bring the protagonist and Mitsuki closer together. Their relationship can develop through their shared experiences and activities at the shelter, while Mitsuki's help becomes an important part of surviving.
Eventually, the pair must turn their attention toward escape. By gathering enough resources and building a boat, they can attempt the difficult journey back to civilization and leave the island behind.