Tras haber salido de prisión y cansada de los cotilleos del vecindario sobre ella y su familia, Suzuko Sato, una joven de 21 años, decide vagar por todo Japón, estableciéndose en un lugar hasta que ahorra un millón de yenes, momento en el que se marcha a otro destino para vivir nuevas experiencias y conocer a otras personas.
Masaki is about to move to the U.S. with his parents, much to the dismay of five girls who all like him in different ways. Tomboyish Takako always gives him a hard time; Haruna is a childhood friend; Alisa has fancied him since a shopping trip in nearby Shibuya; Naoko is still readjusting after a long spell in the U.K.; and Yumi ikes practicing basketball with him at night. All wonder who his "special girl" is, but Masaki isn't saying.
All set to enjoy their day off, three high school friends, Yukino, Asako, and Natsu, board a seemingly normal train... when suddenly, a deafening sound and a flash of light envelop them!....But the three arrive at school the next day as if nothing happened. And yet, something is not right....They see oddly familiar faces, their families are out of sync and they are chased by strange men in black. Plagued by these nightmarish sensations, Yukino flees, only to find herself in front of the amusement park they were heading to on that fateful train ride. Slumping to the ground, Yukino comes to a strange realization....They are stuck between nightmare and reality, between the walls of two worlds that are closing in on them. But which world is real...?!"
