The term was used from the end of the Heian Period to the beginning of modern times, and in the Edo Period the son was called heyazumi (literally, a person living in a room)
平安時代末期から近世の初め頃まで使われた語で、江戸時代に入るとこれを部屋住み（へやずみ）と呼ぶようになる。