Bunchô, Courtesan and Secret Lover, ca. 1770. A famous Yoshiwara courtesan, Morokoshi, with a combination of apprehension and coyness comes out to see her secret lover. Morokoshi's apprentice--sleeve falling open--stands watch for anyone who might be coming their way.
Notice red color of the inner lining of the women's sleeves. And, notice that while Morokoshi is pulling away from her secret lover, he has his hand in her sleeve, which she nevertheless extents to him. This depiction of the sleeves was not random.