"Appa?" Hanna questioned half shouted 
"What? It's true! because of him, I feel so betrayed." Lee Appa said 
"Appa, its been more than 8 years already. Put aside your ego, Youngbae oppa is barely alive" Hanna said sobbing 
"Do I care? Hell No!!" 
"He's your son Appa! Even not by blood but he still your son! The child you care the most for 2 years before Seungri oppa is here" Lee Eomma rubbing Hanna's back soothing her down.
"Yes, he's my son before he dropped out from Medical College without let me know and use that guy from Choi family to fool me until I let him go to Berlin! What the hell? Is that your lovely long-lost brother Hanna? Is he?"
"You still young and you know nothing about this!"
"But..." 
"Shut up!" Lee Appa shouted at her and left the house banging the front door harshly.

Dong Youngbae was adopted by Lee family when he was 2 years old from Angels Orphanage. They decided to adopt him after 5 years married but they still can't bear children. After 2 years Lee Eomma finally got pregnant and it makes the couple so happy. Without neglecting Youngbae they raised both of them together with Hanna that comes 2 years later on. 
Three of them are very close to each other. Their parents treat them nicely and provide everything for them. Youngbae knew that he's adopted son when he was 10 years old.

"Youngbae-ah, let Appa tell the truth.. Actually, you're our adopted son." 
He just remained in silence, don't know how to react. 
"I never thought about this Appa. So who's my parents? where are they?" he asked with sobbing voices
"Your parents were involved in an accident when you were 6 months old. You are the only one who saved in that accident and it's like a miracle. Later, you were sent to Angels Orphanage and we take you as our son when you were 2 years old." Eomma added
"Bae hyung isn't Ri hyung?" Seungri asked puzzled 
"He's your hyung. You'll understand one day." appa said

Youngbae feels so lonely once he knew that he's actually a 'stranger' in Lee family but they never abandoned him. They treated him equally, provide education and everything. Until the day Youngbae was thrown
out from the house when he was age 17. He entered Medical College as how Lee Appa wished but then after 2 semesters, he keeps failing most of the subjects until he was dropped off from the college. Afraid to tell the truth to his dad, he asked his best friend, Choi Seunghyun who is the son of the medical college director to lie his dad, by telling him that he will be going for exchange students programme in Berlin. Unexpectedly