he; boyfriend

one day

first experience (doing something) / (euphemistic) first sexual experience

unexperienced; something one has not experienced before

happening once a year

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