Save me from this cage of infinity Takeshi Kuranari, an ordinary college student, visits the underwater theme park LeMU. An accident occurs, trapping Takeshi and 6 other individuals inside LeMU, 51 meters below the surface. With no hope of rescue, Takeshi explores LeMU along with the mysterious girl Tsugumi and part-time employee You, searching for a way to escape to the surface. A theme park of dreams and hopes sunk in the depths of the mysterious blue ocean. Can dreams and hopes still be found there? Or is there some other mystery lurking? Overcoming one crisis after another, they search for a way to escape.