'Third Charm' tells the love story between On Joon Young and Lee Young Jae over 12 years, from the ages of 20 to 32. Joon Young is a 20-year-old university student who is neat, a good student, wears relatively unassuming glasses and clothing. He doesn't care about fashion. Joon Young plans more than necessary, overthinks things, and is sensitive. Joon Young then takes part in his first blind date where he meets Young Jae and they begin to date. Young Jae is also 20-years-old, is emotional, spontaneous and honest. She's an orphan, although she's very close to her older brother. They live together and rely on each other. Her dream is to become rich and she works as a hairdresser's assistant instead of going to a university. A friend drags her to a blind group date with a university student. There, she meets Joon Young who has a completely different personality than her, and they begin to date.