Kenji and his wife Karen are living together as newlyweds in a small apartment. Their father-in-law, Tooru, is worried about them and comes to their new home bringing gifts. At first, it's to support the young couple... But as he looks at the beautiful and busty Karen, Tooru's desires are aroused. Then, when Tooru goes to pick Karen up from her workplace, he turns into a "wolf in the house." He sucks her overflowing breasts to his heart's content. From then on, Tooru waits in his car every day for Karen to come home...