i-adjective
nostalgic; dear; fondly remembered
Slang adjective derived from 懐かしい (natsukashii). Used in casual speech to express that something brings back fond memories or feels beloved. Often used by younger speakers.
See also: 懐かしい
この曲、めっちゃなつい！
This song is so nostalgic!
昔のゲームをやってたら、なつい気持ちになった。
Playing an old game made me feel nostalgic.