Red Castle Lullaby by Taizō Fuyushima

1960 movie directed by Taizō Fuyushima

A 16-year-old youth is ordered to commit ritual suicide to follow his deceased lord into death and preserve the honor of his clan. His elder brother's wife, who has raised him as if he were her own child, asks her husband for permission to spend a single night with the young man and teach him the pleasures of the flesh, out of motherly mercy. However, the following day, an official decree is issued to ban suicide through fidelity...

A gangster gets released from prison and has to cope with the recent shifts of power between the gangs, while taking care of a thrill-seeking young woman, who got in bad company while gambling.

The plot is based on the novel "Akechi Samanosuke no Koi," the final work in a trilogy by Hiroshi Kato about the forced suicide of Oda Nobunaga at the temple Honnoji. Historically, the general Akechi Mitsuhide is credited with causing Nobunaga's downfall. Kato's novel focuses on Mitsuhide's nephew Samanosuke, who fought alongside his uncle during the assault on Honnoji.