Nagi Machi seems to be a vehicle to show off the edgy acting skills of post-SMAP Katori Shingo, shedding his 'idol' skin to play a paunchy gambling-addict who manages to create more guilt and regret in his already over-burdened life. That aspect is the film's one successful element. Katori has range and depth, and does a sterling shift here potraying the complexity of a man filled with self-loathing and unable to break free of addiction, or overcome regret. The character is cut from the same cloth as Casey Affleck's in Manchester by the Sea.
The problem is, all the other elements beyond Katori's performance are woefully inadequate (with the exception of the acting by other principals, which mostly holds up). The script meanders along and lacks any sense of pace. It is both strangely un-involving and sentimental. There is a murder, but the characters interact in roughly the same tone and emotional level in scenes before and after the murder. If you pluck a scene at random and ask someone who has not seen the film to guess if the scene came before or after the murder, they would be baffled. There are cartoonish one-note yakuza, a taciturn old fisherman who lacks any sense of reality, and a schoolgirl daughter who seems to make only one friend, and only because he recognizes her from childhood. Katori's character battles gambling addiction, but the scenes of him betting are cookie-cutter, repeating the same information and in no way growing or progressing the narrative. There is the cliched, drink-too-much-and-fight-too-many-guys scene of self-destruction, taking place at a summer festival. No doubt the festival was re-created to add colour and culture, but nothing else in the film says 'summer.' The murderer is depressingly easy to spot. The cops are as sloppily written and as one-note as the yakuza. The camerawork goes hand-held too often and for random reasons. Slow-motion is employed at inappropriate moments, most noticeably when the characters react to the murder. The music at this point is also wildly unsuitable.
In a truly sinful movie, the most egregious sin is setting this in post-tsunami Miyagi, and yet giving no sense of how people are coping - or failing to cope - with the aftermath. Every now and then the film nods at 2011, such as a comment about a sea defence wall being built, but most of the time this film could be happening anywhere. That rich present-day Tohoku storyworld is under-utilized, or more accurately ignored, and it feels like a violation. The end roll plays over real-life underwater footage of the wreckage from the town that now litters the sea bed. This is a final nod to the location and the tragedy that feels too little too late, and is tonally out of sync with the banal melodrama we have just witnessed.
In short, a decent addition to Katori's showreel, but otherwise uninteresting.