18 Year Old Joo ah’s Hot Day

Eun-hye is a substitute lecturer. One day she is freaked out by being stalked and calls her cousin in to live with her as her bodyguard.
Kang-tae is a test repeater and he’s impressed with how hard working Eun-hye is and starts feeling fond of her. One day, he drinks with his friend Tae-bum and gets drunk while talking about his cousin.
Tae-bum carries Kang-tae home and falls in love with Eun-hye the moment he sees her.