The film tells the story of life in Tom Hanson for 500 days from January 8 when the summer finder came to work in his office. The summer comes from Michigan and doesn't immediately notice Tom, while the young man himself realizes that this meeting is fate. Their first short conversation takes place in a lift, when it turns out that summer loves the same music as Tom. The first meeting is followed by the other, the other is followed by another, and soon the couple begins to meet. However, summer does not want a serious relationship, as he treats them more easily and freely than Tom. She does not believe in love, does not like to notice, that is, she does not like being someone's girlfriend. Tom, in turn, understands that he is just looking for serious relationships. This difference in character leads to the crime in their relationship on the 290th day of dating.