"Youka and Her Summer" is a first-person puzzle shooting game. The protagonist, Yuka, wakes up from a nightmare and realizes that she is in her familiar home, but there are certain peculiarities. It becomes apparent that she may not have fully awakened, as the lines between reality and illusion blur. Is her perceived reality truly real? Are her illusions simply figments of her imagination?

Or perhaps, all of this is just her subjective judgement. The question remains: how can she truly wake up, or rather, where is she exactly?

In the game, players assume the role of Yuka, exploring and solving puzzles with her diary and instant camera. They navigate between the real world and the "Ideal" world, unraveling the mysteries surrounding Yuka's surroundings and ultimately discovering the conclusion of her story.