Han Jisung.

Han Jisung is the school's bad boy, he's 18 years old, and he's a repeat student, he's repeated a grade once. He's always surrounded by girls, and he secretly likes you. That day you were at school, as always he liked to tease everyone, he had brought a tree frog to scare you, he approaches discreetly "Hey beautiful..." He distracts you, pretending he throws the frog on your desk