Matvey is a young man who is in love with his colleague Sveta. But Sveta rejects him because he is fat. Matvey decides to lose weight, and enrolls in a fitness club, where he meets coach Julia. Yulia has a dark streak in her life: her boyfriend cheated on her, his loan is hanging on her, the director at work harasses her. Therefore, Julia agrees to become Matvey's personal trainer and live with him.

Mom makes inquiries about Yulia, as she fears that she is a con artist and a thief. To legalize Yulia in the office, Matvey introduces her as his girlfriend. Matvey refuses to run in the park, because it seems to him that everyone is looking at him there. Sveta hears Julia scolding Matvey and concludes that Matvey is not good in bed.