青あお線せん区く域いき

noun

blue-line area; illegal prostitution zone

Historical term for areas marked with a blue line on police maps where illegal prostitution occurred, roughly from the 1940s until the 1956 Anti-Prostitution Law. Often contrasted with 赤線区域 (red-line district).

See also: 青線地帯

• 戦せん後ごの東とう京きょうには、青あお線せん区く域いきと呼よばれる場ば所しょがいくつも存そん在ざいした。

  In postwar Tokyo, there were many places called blue-line areas.

• 青あお線せん区く域いきは、警けい察さつの地ち図ずで青あおい線せんで囲かこまれていたことからその名ながついた。

  The name 'blue-line area' comes from the fact that these areas were enclosed by a blue line on police maps.