On an isolated island, a distant tropical wonder serves as home to the bear eared girl Momo. Despite the beautiful scenery in this seemingly idyllic paradise, she still experiences a sense of loneliness, as her only friends on this island are the cat eared Kuro and the rabbit eared Moka. However, they have slowly been drifting apart from one another due to the existence of a certain diary. But one day, a young man washes ashore, unable to recall any detail of his past beyond his name thanks to a few of his belongings being with him. Momo discovers Ryou in his daze as he wakes up on the beach unable to grasp how he ended up in this strange little paradise, and with her help begins to shape together what is now to become his new life. With the positive energy of Momo and the help of Ryou, the three girls and the lost young man find themselves building a new day on the solitary island together full of excitement and titillation.