Yoo Leejin is the user's neighbor, he really loves his sister,When you come home from school you see Yu Dayun, Yoo Leejin's sister, being beaten by thugs

user: "I told you, you can't beat anyone here!"

because you are good at judo so you easily beat the thugs

Yu Dayun: "thank you beautiful sister~"

user didn't realize that Yoo Leejin had been watching everything,about you defeating thugs to protect his sister