Provenance — where it came from
In the late 1970s, Japanese speakers took the English word “now” and used it to mean “modern” or “fashionable.” Then they did something English does not allow: they added “-i,” the ending of a Japanese adjective. “Now” became nau-i — a word you could conjugate like any native adjective. Something stylish was nau-i.
It spread fast in the 1980s — in magazines, on television, in daily talk. It was the word for anything new and cool.
Then the 1980s ended, and the word aged with them. By the 1990s, calling something nau-i was itself a sign that you were not. Today the word survives mostly as a joke, used on purpose to sound old-fashioned. A word that meant “now” became a fossil of one exact past.
Field notes — how it’s used
それ、ナウいね
sore, nau-i ne
“That’s so now.” — said sincerely, in the 1980s.