Mirai Asahina leads an extremely ordinary life as a college student, while secretly—and magically—helping people as Maho Girl. However, one day, a giant monster appears in Tsunagi Town, where Mirai lives!

Each day, Hisui is growing more and more at an unbelievable rate. To avoid suspicion from those around them, Mirai and Liko take Hisui and move into an apartment that Liko has rented.