''301, 302'' explores the relationship of Song-hee, a chef living in apartment 301, and Yoon-hee, an Anorexia nervosa writer living in apartment 302. The film begins with a detective visiting Song-hee to investigate the disappearance of Yoon-hee. The detective questions Song-hee about Yoon-hee's personal life, Song-hee claims that Yoon-hee has no interest in food or sex. He then searches Yoon-hee's empty apartment. The film shows Yoon-hee in the spaces around her home that the detective explores. The detective finds her anorexia medicine and her written work on the subject of sex.