Yuko Shiraki's second Ruby exclusive features mother-son sex! After a divorce, the father and mother share their two sons. The older son grows up to be a responsible member of society, while the younger son doesn't get along with his wild father and leaves home. Soon after, the father passes away, and the two sons are reunited at the funeral. Yuko goes on a hot spring trip with Tsubasa, whom she has reunited with for the first time in several years. Tsubasa's love, craved for his mother's affection, has become distorted. Tsubasa makes advances on his mother...even though she knows it's wrong, she accepts it...