Yosuke Ohashi (Yuki Izumisawa) has just started dating Ayako (Natsuko), who is four years younger, two weeks ago. When he enjoys dating at a coffee shop, he receives an unannounced call on his cell phone. As Yosuke tries to ignore his incoming call, a disturbing air flows out. Prompted by Ayako, who was distrustful, Yosuke answered the phone, and the caller was a stranger woman. Dismayed Yosuke is suspected of having an affair by Ayako and is shaken. The woman, a suicide applicant, was calling her appropriate number. She says she's discouraged from dying if the other person comes out. The woman offers a game to her embarrassed Yosuke. If she asks the coffee shop master (Ryo Iwamatsu) to say, 'I'll call the police,' Yosuke wins, and if Yosuke loses, the woman cuts her wrist and dies. The command of the woman who took her own life as a hostage escalated more and more, and the 'unbreakable phone' that she wanted to hang up drives Yosuke.