From being the high school valedictorian to a college wild-child who's attended more parties than classes, hooking up with the wrong guys and sleeping with another girl's boyfriend. Ahn Shin Ah had an easy life, but everything changes when she learns her parents were killed in a tragic accident, making her the instant mother of her two younger brothers. It's not that easy, though – she'll have to fix her image, her life, her GPA fast to keep them out of foster care!

Mr. Byun Baekhyun is the TA for Shin Ah's history class. He's quite familiar with Shin Ah's slacking off and after her stupid mis-sent text, it sparks the sudden – if you could call the banter and brutal honesty between them – friendship. But who knew her uptight TA could also be a great tutor and babysitter? And he helps offer her some guidance with not only school things, but also things she can't necessarily control.

It's not long before Shin Ah realizes having a responsible adult type around has its perks... and she'd like to do some irresponsible things with him now. Good thing he's not that kind of guy who'd ever reciprocate.