hobby friend; friend through shared interests
Colloquial noun for a friend made through common hobbies, tastes, or personality. Often used in casual conversation, especially among younger speakers.
See also: 類は友を呼ぶ
We share the same hobbies, so we quickly became hobby friends.
SNSで類友を見つけるのは簡単だ。
It's easy to find friends with common interests on social media.
Abbreviation of the proverb 類は友を呼ぶ (birds of a feather flock together). The exact origin as a standalone noun is uncertain, but it emerged in colloquial speech.