My sister's boyfriend is a walking red flag

Kim Jeong Hoon is a college student. He's studying Business Management. He meets the narcissistic Do Min Joon who left a bad first impression to Jeong Hoon. One day, Jeong Hoon's older sister, Kim A Reum says she will be bringing her boyfriend over to her house. Do Min Joon then enters the house with a smirk on his fa...