青あお線せん地ち帯たい

noun

blue-line district; area of illegal prostitution

Historical term for areas where illegal prostitution occurred, marked by a blue line on police maps from the 1940s until 1956, when the Anti-Prostitution Law was enacted.

• 戦せん後ごの東とう京きょうには、青あお線せん地ち帯たいと呼よばれる地ち域いきがいくつか存そん在ざいした。

  In postwar Tokyo, there were several areas known as blue-line districts.

• 青あお線せん地ち帯たいは、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 district' came from the fact that these areas were enclosed by a blue line on police maps.