The Neighbor No. Thirteen - Plot

Plot

Juzo Murasaki (Oguri Shun) arrives at a work construction area to take on his new job as a construction worker. To his quiet dismay, his supervising boss turns out to be Toru Akai (Hirofumi Arai), who with his gang had made Juzo's middle school life a living hell. Akai, however, doesn't recognise Juzo.

Juzo's more disconcerted when he discovers that Akai lives with his wife, Nozomi Akai (Yumi Yoshimura) and their toddler son above Juzo's new apartment. As Juzo emotionally struggles to handle these unexpected developments, a mysterious and seemingly malicious hooded figure appears. It calls itself Number 13 (Nakamura Shido).

As Juzo attempts to control increasing number of flashbacks and a spiral fall into psychological darkness, Akai constantly picks on Juzo and other work colleagues including Seki Hajime (Tomoya Ishii), a former middle school student who becomes Juzo's casual friend in spite of Juzo's anti-social tendencies, at work. Meanwhile Akai's wife, Nozomi, attempts to make friends with Juzo and entrusting the care of her toddler son to Juzo. She proudly shows Juzo her husband's school photos. In one class photo, Juzo's space is marked with an X to show he was absent. Juzo suffers a severe flashback to explain his absence that day: in their school's science room, Akai and his friends have thrown acid at Juzo's face.

Seki becomes suspicious about Juzo's increasingly odd behaviour and goes to inform Arai at the work site, but Arai dismisses him without giving him a chance to speak. During this incident, Seki doesn't realise he's being watched by Number 13, but as soon as he does, Number 13 kills him. Similar incidents follow, which eventually attracts Juzo and Arai's attention.

Number 13 takes Nozomi's life and kidnaps her toddler son. After finding their bodies, Juzo knows where Number 13 has disappeared to: the middle school. At the same time Akai, now knowing who Juzo is, discovers his wife's body and his son missing. He also goes to school. Having arrived first, Juzo discovers what happens to the toddler son, whom Number 13 forcibly drowned, and realises it's gone out of control.

He goes to confront Number 13, but by then, Akai arrives and attacks Juzo whom he believes has his son. After a violent confrontation, Juzo—who we realise is Number 13 all along—kneels over fallen Akai. As he is about to bring down a weapon upon Akai's head, Akai shouts out an apology. Juzo freezes. The apology splits Juzo's universe into two.

Universe #1: as described above.

Universe #2: as middle school boys, Akai apologises after Juzo stood up against Akai's bullying. Soon after, Juzo appears in a class photo as a quiet but happy-looking middle school student. As an adult, he walks past an apartment block where he and the Akai family lived in Universe #1. Juzo notes some construction workers are taking down the block sign, which hints the block is slated to be demolished, then he spots a dark figure in a window. It's Number 13, but Juzo doesn't recognise him as he looks away and continues walking along the side of a man who appears to be Juzo's work friend. It's Arai.

At this point, we viewers realise that the events we saw in Universe #1 never took place in Universe #2. Universe #1 is a scenario of what could have been if Juzo hadn't won Akai's apology after standing up for himself on the day of the potential acid incident and their school photo session. The acid incident, if Juzo had failed to stand up for himself, could have given birth to Number 13, thus creating Juzo's path to Universe #1.