High school may be tough, but Woo-hyun (Nam Woo-hyun) has a guardian angel looking over him — literally. Disguised as a naive high schooler, Lee Seul Bi (Kim Sae-ron) descends from the heavens to protect Woo-hyun's life, but discovers she's got a thing or two to learn about life as a teenager, including the pains of falling in love. Can this cherubic guardian protect the apple of her eye and also manage to survive high school?
Woo Hyun distracts Lee Seul Bi while she's trying to do her "job", causing her world to go awry.
Knowing no one else in this world Seul Bi needs to stick close to Woo Hyun and his family.
As she continues living as a human, Seul Bi has to start doing things normal kids her age do.
Seul Bi starts to deal with the negatives of being a human.
Romantic feelings are in the air and everyone just needs a little push to make them known.
Woo Hyun makes his feelings for Seul Bi known but she doesn't know how to respond.