Nijiro Murakami (Destruction Babies) stars as Toru, an aimless college student who stumbles upon the aftermath of a murder scene one night, and without thinking, grabs the titular weapon. He takes it home and keeps it safely hidden away, but curiosity gradually begins to consume him. His budding relationship with a sunny fellow student suffers as his obsession grows, and he becomes more and more reclusive. And when a detective (Lily Franky, Shoplifters) turns up at his apartment, a dangerous cat-and-mouse game ensues. Take Masaharu (100 Yen Love) adapts a prizewinning novel for this noir-tinged tale, shot mostly in luminous black and white.