암호는 002!

The night before Su-Jeong plans to confess her feelings for Do-Jin, she runs into him on the street and is devastated to find out that he doesn't even know her name. Too afraid to face him in class the next day, Su-Jeong hides in the storage locker, where she meets Do-Jin's younger brother Jae-Yun. With Jae-Yun's help, will she able to win Do-Jin's heart? (Source: WEBTOON, edited) Note: Includes four extra chapters.