For Yumi, who had raised her son with a single woman's hand, her son was an irreplaceable treasure. That's why he didn't show his son any troubles. His son knew it, or he supported Yumi very hard. However, Yumi had a more reliable fiance than anyone else. it was my son's best friend... When he gives him a hot love affair, the brain that should have been full of his son is gradually filled with the presence of a loved fiance.