Tsubasa had a good relationship with her husband's child and was living a happy life. The only concern that threatens this happiness was Tsubasa's own outrageous propensity to turn into estrus and de lewdness immediately when she saw a big cock. A bad habit can destroy a family... Tsubasa has played the role of a good mother by carefully hiding her habits. However, one day, by chance, she finds out that her son-in-law is the owner of the big cock...