Many similarities to Imamura's The Pornographers

In some ways The Eel is almost a remake of Imamura's 1966 film The Pornographers (Erogotoshi-tachi yori: Jinruigaku nyûmon). It also takes place in a ramshackle barber shop and has many similar elements: sexuality, adultery, psychological impotence, a dead spouse, a pet fish (believed to be the reincarnation of the dead spouse), a woman named Keiko whose mother has business investment money and is in a psychiatric hospital, chanting Buddhists, and an element alluding to the bizarre (similar to the UFO-hunting), which I won't spoil.

Ozawa Shoichi who plays the main role in The Pornographers has a cameo in The Eel as the gynaecologist.

The Pornographers is a much better film: visually more stylish (mid 60s new wave, in glorious black and white), with a better soundtrack, better pacing, a more interesting story and more emotional intensity, with none of the sentimentality that ultimately blemishes The Eel.