A lonesome college student name Jiro (Keisuke Koide) is spending his 20th birthday alone when suddnly a beautiful cyborg girl (Haruka Ayase) turns up. The few hours that he spends with her are the most incredible moments of his life and Jiro is overwhelmed by his good-fortune in meeting her. But his happiness does not last for long since she disappears after that. A year later on his 21st birtday, Jiro runs into her again. At least she looks the same, but this time she is somehow different. It is beginning of love that would change his life forever..