On that island lives Mikuru, a middle school second-year student who is 15 meters tall…! Shigeru, who moved from the city, finds Mikuru's presence incredibly enjoyable. They quickly become friends, and along with Rin-chan, who is the class representative type, the three of them enjoy life on the island. In volume 3, Mikuru, who initially wanted to keep her existence confined to the island, starts to feel the desire to express her thoughts not just to the island but to the world. What is the reason for this change of heart?! A school comedy where the friendship of the three paves the way for a new era, here it concludes!