All the relatives gather for the New Year. After a brief exchange of greetings, alcohol and delicious food are served, and the house is in a festive mood. However, two sets of parents and children are not at peace in the midst of all this... The aunt and nephew of the Yabe and Nanami families have been in a relationship for some time. The four of them have no idea that the parents and children are actually in a physical relationship, and they have been looking forward to this day, the only day of the year when they can meet openly. The two sets try to keep things secret from the other relatives... but unfortunately they run into each other, and finally find out the whole truth...