My Boyfriend is Type B is a South Korean romantic comedy film from the year 2005. The basic premise of the film comes from the Japanese blood type theory of personality, which claims that a person's blood type can determine their personality traits. The heroine is type A (conservative and introverted) while her love interest is type B (passionate and irresponsible).

Young-joon and So-yeo are a young couple with their marriage relatively stable. On a day their mutual friend opens a wine bar, they come across Min-jae and Yu-na, a couple quite the opposite of themselves.