On the opening day of Shin-Yoshiwara — Edo's new pleasure quarters — Matsunaga Seiichiro, a 26-year-old swordsman stands on the Asakusa Nihon Embankment and looks across at the city. He then descends into streets filled with music, danger, alcohol and prostitutes, and thus begins his journey to manhood and power. Ostensibly, he is a naif from the country, one with deadly weapons, but he has a secret known only to a select few — he is the son of ex-emperor Go-Mizuni-in and his sword is none other than Oni-kiri — the Demon Cutter.
Within the hour on the streets, he is attacked by boisterous samurai and meets Gensai, an old man, who introduces him to the women of the quarter and becomes his guide to this peculiarly Japanese heaven and hell.
The novel is — forgive me — a swords and sorcery tale set in the 17th century. Seiichiro is introduced to the delights and demons of the pleasure quarter. He meets four women during his stay: the famous courtesan/ninja Katsuyama; the 9-year-old spiritual medium Oshabu, who believes she is destined to be his wife; Takao, a beautiful courtesan who forgoes the tripartite conventions of wooing Seiichiro in order to sleep with him on the second meeting; and a time-traveling succubus in her 80s who summons up the past during sex as she transforms into a beautiful young woman.