Ishida Umi

Middle schooler Ryunosuke is visiting his grandmother's house on an island. As Ryunosuke walks past the stairs leading to the second floor at his grandmother's house, a strange, plant-like thing extends down from above. Intrigued, Ryunosuke tries to climb the stairs, but his uncle stops him with an unfamiliar expression, saying, "What are you doing?" and "You'd better not go up." That night, however, Ryunosuke's curiosity drives him to go upstairs after all...

—That summer, we found a “monster” with the face of a girl. A secret between two boys, something they couldn't tell adults. To them, it was a creature of their imagination. Until that summer— Ken, cautious and timid, and Shun, bold and fearless. What the two boys found at the beach was a girl who was a “mermaid”, a being said to be “a dangerous presence” in their village. “Even if you see it, never go near it.” Will this encounter bring tragedy? Or— “You don't eat humans, do you…?”

Two lonely sisters and a mysterious creature. They begin a family life that is kept secret from the adults. One day, two sisters abandoned by their family meet 102-chan and Zero-san, two people with mysterious powers. Though they are afraid of them, as they live together, the sisters experience the warmth of family for the first time. But one day, their existence is on the verge of being discovered by the townspeople. ‘The humans who abandoned them’ or ‘a different species that acts like family’, what will the sisters choose……? This heart-wrenching story asks the question: “What is a true family?”.