noun
strange thing; eccentric taste; red eboshi
Literally 'red eboshi' (a type of court cap), but used idiomatically to refer to something odd or an eccentric preference. The connection may come from the unusualness of a red eboshi in certain contexts. The literal sense is included for completeness but is rare in modern usage.
See also: 烏帽子
彼の趣味はまさに赤烏帽子だ。
His hobby is truly eccentric.
この骨董品は赤烏帽子と言えるほど変
This antique is so unusual it could be called a red eboshi.
Refers to the black lacquered cap worn by court nobles in ancient Japan. 赤烏帽子 is a red variant, used metaphorically for something strange.
Compound of 赤 (red) and 烏帽子 (eboshi, a type of court cap). The idiomatic meaning likely derives from the perceived oddity of a red eboshi, but the exact origin is uncertain.