An intense adult mystery about youth gone horribly wrong.

It's been some time since Rina Kuriyama (25) was murdered by her boyfriend. One day, her younger sister Reina (14) kidnaps a classmate and violently holds her captive. That same morning before kidnapping the girl, Reina meets Kanako Saeki (25), an old friend of Rina's, hands her "a human body part," then runs off without explanation.

While Reina holds her classmate hostage somewhere unknown, Kanako and her friends desperately search for Reina's location. They also argue over what to do with the disturbing "body part" they've received. Following a clue they find along the way, Kanako's group meets with "a certain man"...

Rina Kuriyama hated Kanako and her friends before she died. Her murder and Reina's kidnapping aren't unrelated events. Why was Rina killed? Why did she resent Kanako's group so much? Why did Reina kidnap her classmate—and why give away that body part?

Connections emerge between Reina's classmate victim, Rina's murderer, "the certain man," and Reina herself—and all point toward Reina's tragic past. Adults struggling with suffocating lives; uncertain futures; unforgettable traumas... All these painful mysteries connect as summer cruelly comes to an end.

This is the final youthful rebellion of adults who can't grow up—and the last summer for a girl who's given up on ever becoming an adult herself.

When you truly become an adult, you accept life's boredom. Sparkling youth won't come again—so let's make one last reckless memory together.

Stagette. Everyone eventually grows up...

[Translated from freem]