The relationship between Okada Takuya (Kitamura Takumi) and his sister Okada Naruko (Matsumoto Honoka) is very good. However, an accident took away Naruko's young life. Unable to accept this cruel reality, Takuya fell into deep depression. After entering high school, Takuya unexpectedly met a girl named Watarase Shinmi (Nagano Meiyu). This girl suffered from a special disease that caused her skin to emit a strange glow. This disease is incurable, which means that Shinmi is stepping towards death not far away. Shinmi's disease has brought a great shock to Takuya. When he learned that Shinmi still had some wishes that he didn't understand, he volunteered to announce that he would accompany and help Shinmi realize his wishes. In the process, the two created countless unforgettable happy memories. Under the gravity of death, the two hearts are getting closer and closer.