夏美（韩智慧 饰）是A型血型，非常胆小，而她非常期待能有一段浪漫的爱情。每天祈祷的她终于在某天遇到了梦中情人。 迎彬（李东健 饰）是一名年轻的男孩，面子对他很重要。B型血的他表面上落落大方，实际上他是自私幼稚的。夏美遇到了迎彬一系列浪漫的追求，不顾家人反对的夏美与这位白马王子走到了一起。恋爱一开始是甜蜜的，但时间长了，夏美便发现了自己男友存在的缺点。终于无法忍受，夏美只好忍痛分手。到底迎彬还是意识到自己的问题，便决心改过缺点以能重新得到夏美的欢心。 但夏美是个做了决定便不愿回头的人，迎彬将会如何面对固执的夏美呢？Young-bin and Ha-mi meet by accident after a row over him ruining her cellphone. She believes he and she were destined to meet, but the problem is, he has blood-type B, making him spontaneous and emotional but unreliable. Her sister, running a dating-agency based on selection by blood-types, opposes the friendship, as she's convinced that Ha-mi, with blood-type A, making her soft, introvert and shy, will only end up as another victim of his whims and arrogance. Romantic comedy by Seok-won Choi.
