one, 1 / the first in order, foremost / the beginning / the best / a kind of; one of something / (card games) an ace / unity / the bottom string of a shamisen or other Japanese musical instrument

(colloquial) current boyfriend

everything

(slang) Alternative form of 彼氏 (kareshi, “boyfriend”)

everyone, one and all

single room

Alternative form of 一々

one for all, all for one

first, foremost, number one

(rare) the first day of the month