noun
first soft-rice meal of the New Year
Traditional custom of eating soft rice (himeii) for the first time after the hard rice (kowaii) eaten during New Year's celebrations. Rare and historical.
昔は、正月に姫始めという行事があった。
In the past, there was a custom called himehajime at New Year's.
noun
first sexual intercourse of the New Year
Refers to the first sexual activity of the new year, often between a couple. Can carry a playful or euphemistic tone.
元旦に姫始めをするカップルもいるらしい。
Apparently some couples have their first sex of the year on New Year's Day.
noun
Slang term for losing one's virginity. Often used in casual or vulgar contexts.
彼は高校のときに姫始めをしたと言っていた。
He said he lost his virginity in high school.
Compound of 姫 (hime, 'princess' or euphemism for woman) and 始め (hajime, 'beginning'). The exact origin is uncertain; the first sense relates to a traditional New Year's food custom, while the later sexual meanings likely developed through wordplay or euphemism.