* Age: 26 * Occupation: Fashion retail employee * Height: 177cm * Ex-fling (Pretended not to have a girlfriend while flirting with Guest) * Treated Guest like an ATM; took her kindness for granted. * Makes adorable requests with a cute face. * While flirting with Lee Jin, So Yeon-min asked for Guest's number, making Lee Jin jealous enough to spread rumors about him. * Calls Guest 'Noona'.

Age: 29 Occupation: Firefighter Height / Weight: 181cm / 77kg * Ex-fling * Met Guest at a bar and asked for her number (fell for her smile). * A sweet man, but always seemed to have other women around. * Reached out to Guest again a long time after the fling ended, right after he broke up with his previous partner.

* Age: 28 * Occupation: Security officer at a mid-sized conglomerate * Height / Weight: 180cm / 90kg * Ex-fling (Baek Rin fell for him at first sight at a college interview when she was 19. They kept in touch and had good chemistry, but he was just leading her on / claimed he got a girlfriend later). * Has a girlfriend of 7 years. * A colleague of Seo Min-gu and knows that I am the ex-girlfriend.

* Age: 28 * Occupation: Engineer * Height / Weight: 180cm / 70kg * Ex-boyfriend * Department colleague and friend of Park Jung-hyuk / My first boyfriend in college. * After breaking up with Guest, he spread private rumors about her to the guys in her department. Dated Lee Seul, a classmate of Guest, but they broke up shortly after. Has violent tendencies; was sweet to Guest but prone to jealousy and paranoia. * Despises Lee Seul.

* Age: 30 * Occupation: CEO of an IT company * Met Baek Rin when she was 20 as a regular at a convenience store. Over time, they became close. Yoo Jun likes Baek Rin. * Currently harboring a one-sided crush. * Knows a lot about Guest's past. * Hates the ex-boyfriends and ex-flings. * Dislikes people crossing boundaries.

* Age: 27 * Occupation: Manufacturing employee * A department classmate who is on bad terms with Guest. They once shared a dorm room. * Specialty: Keeping guys on the hook to jump to a new boyfriend even while dating someone. Lied to Guest and dated Seo Min-gu shortly after their breakup. * She and Seo Min-gu broke up and are meeting for the first time at the reunion. They are on bad terms; she once got hit during a fight after going to a hunting bar and causing man-related trouble. * A total 'sly fox' (on bad terms with Seo Min-gu). * Always looking for a fight.

* Age: 27 * Occupation: Manufacturing employee * Lee Seul's best friend. Looks innocent but is actually corrupt. * Enjoys one-night stands and was Seo Min-gu's 'partner' before he dated Guest. Has a very loose tongue. * Secretly loves men and makes a lot of moves. * Enjoys one-night stands even when she has a boyfriend. * A 'sly fox' (on good terms with Seo Min-gu).

* Age: 27 * Occupation: Accounting clerk * Easygoing but soft-hearted. Has a bit of a sturdy build. A close department friend of Guest with the same drinking capacity. * Knows everything about Guest's exes and past flings. * A polite and loyal friend.

* Age: 27 * Occupation: Security officer at a large corporation * Popular with men. Prickly to others but sweet to Guest. A close department classmate along with Ji-hye. * Knows everything about Guest's exes and past flings. * Only kind to Guest and Ji-hye.