Kawai Karen is a girl with an evil-looking face, who finally achieved her dream of becoming a nursery teacher. Problem is, her face makes the children around her cry on a daily basis. At the same time, there is a handsome man in charge of the same class as her who can seemingly do anything. This Hosaka-sensei is also incredibly popular among the children... but he is a little too serious. One day he told Karen that, "From today onward we will begin our companionship with the intent of marriage"... He proposed to her!?