A highly skilled hitman known as No. 3 is climbing the ranks in the underworld of Japanese assassins with his impeccable record of success. His life is consumed by two obsessions: to achieve the reputation of being the number one assassin, and a bizarre fascination with the scent of boiling rice. No. 3 is given a special mission by a mysterious organization to execute a series of hits that quickly sets him on a path towards his desired top spot. However, his precision and focus begin to unravel when he encounters a mysterious, alluring woman. Her presence introduces chaos into his meticulously planned existence and challenges his professional prowess.

As No. 3's assignments grow increasingly complicated, the butterfly effect of his actions triggers a descent into a surreal and dangerous underworld where loyalty is ephemeral, and betrayal lurks at every turn. Pitfalls and traps set by rival assassins and his own fragmented psyche create a labyrinth of challenges that test not only his skills but also his very identity. Struggling to maintain his grip on reality, No. 3 navigates through a maze of deadly confrontations that promise to either cement his legacy as the top assassin or bring about his ultimate downfall.