red line / (historical) Short for 赤線地帯(あかせんちたい) (akasenchitai): Akasen (districts in Japan where prostitution and the sex industry flourished)

"red sheet", specifically a red translucent plastic sheet used in studying to render red-colored text illegible

red brick

Red alpenglow of Mount Fuji in the morning, especially in early autumn.

a red paper lantern, typically used as a sign marking an izakaya, an inexpensive Japanese pub / (figuratively) an izakaya

a red papier-mâché bobblehead cow toy, a kind of regional omiyage regarded as symbolic of the Aizu region of Japan

red lead

(obsolete) Soviet Union

(mahjong) red tile; unique to Japanese mahjong and used to score bonus points

(astronomy) right ascension