Under the shade of an ancient tree, four schoolboys – Junichi, Makiko, Keisuke, and Naoto – concealed a weapon beneath the soil. Twenty-three years passed. Now a detective, Junichi found himself unexpectedly reunited with Makiko.

Nara and Junichi reviewed the supermarket’s security recordings and phone records. Afterward, Junichi brought up the idea of unearthing their old time capsule with the others.

A rising tension settled amongst Junichi’s friends as they realized the gun was gone from the time capsule. It was Keisuke who finally persuaded Makiko to report the disappearance to the authorities.

Nara began to suspect a link between the current investigation and events from years gone by. Meanwhile, Junichi discovered that Keisuke’s vehicle had been spotted close to the burial ground.

As Naoto’s carefully constructed alibi began to dissolve, Nara requested he come to the police station of his own accord. Yet, lingering questions persisted—regarding the time capsule and the murder weapon.

The revelation of a secret Naoto had guarded for twenty-three years left Junichi reeling, forcing him to confront a fault of his own. Detective Nara requested the presence of another individual for questioning.

Standing where the tragedy had unfolded twenty-three years before, Makiko and Keisuke were struck speechless by what Naoto revealed. Nara’s voice, low and urgent, cautioned them: this was a truth that must remain hidden.