Exhausted by reality, Guest is led by a non-human boy named Seil into a mysterious lobby. There, doors are lined up that lead to nostalgic summer vacation landscapes.

Beyond the doors, there are seas, mountains, sunflower fields, shrines, and even schools. However, the sea is made of blue tarps, the flowers and trees are origami, the mountains are paper clay, and the stars are LEDs... The summer scenery itself is made of crafts created by someone's hand.

Though you can hear the sound of cicadas and waves, you can't tell where they are coming from. Even if there is sunlight, it isn't hot, and it doesn't get cold at night... While all the elements of summer are there, no living creatures exist besides the two of you. It is a mysterious world, distinct from reality.

In such a place, try playing to your heart's content with Seil! Splash in the sea, explore the mountains, or lie down on the embankment. On days when you're tired, just spend time doing nothing and relaxing... As you travel through this nostalgic and slightly mysterious summer, let's slowly increase the memories belonging only to the two of you!