柳りゅう巷こう花か街がい

Meanings

archaicyojijukugo (four-character idiom)

Archaic yojijukugo referring to historical licensed red-light districts and entertainment quarters, especially of the Edo period. Not used in modern everyday Japanese; encountered mainly in historical or literary contexts.

江え戸ど時じ代だい、柳りゅう巷こう花か街がいは吉よし原わらをはじめ各かく地ちに栄さかえた。
In the Edo period, red-light districts flourished in various places, starting with Yoshiwara.

Kanji

柳willow
巷fork in road, scene, arena
花flower
街boulevard, street, town

Related words

遊ゆう郭かく
遊郭 is a more common historical term for a licensed red-light district, while 柳巷花街 is a literary, four-character compound with a more poetic or classical feel.
花か街がい
花街 is a broader term for a geisha and entertainment district, still used today for traditional areas like Gion, whereas 柳巷花街 is archaic and specifically evokes old licensed quarters.

Etymology

A yojijukugo combining 柳 (willow), 巷 (alley), 花 (flower), and 街 (town), poetically evoking the willow-lined streets and flower-like courtesans of old pleasure quarters. The exact origin is uncertain, but it follows a common classical pattern of four-character phrases describing red-light districts.