The Tsuki couple are in their third year of happy marriage. One day, when her husband is transferred overseas, his wife Ruisa decides to attend the English conversation class at his company. Ruisa feels renewed energy from the gentle and passionate English teacher Mike, a black teacher. One day, Ruisa takes a drunk Mike to a hotel and witnesses his shockingly thick black penis... Slender beauty with big breasts, Tsuki Ruisa, has her first ever black man sex!