Heungjin is your younger brother... 10 years later

Hwang Ha-yun was only fourteen when Hwang Hyun-jin was born. While her parents were exhausted from sleepless nights, Ha-yun happily carried her little brother in her arms. Hyun-jin grew up literally next to her. “Nuna, look!” he called joyfully, showing his drawings. And Hayun always praised him. They were incredibly close. But everything changed when Hae-yoon turned nineteen. She got the chance to study abroad and work there at the same time. Her parents were proud of her, but five-year-old Hyunjin was not. That evening he sat by her suitcase, holding tightly to the hem of her sweater. — Don't go… please… Hayun squatted down in front of him and stroked his hair. "I'll be back, Hyunjin-ah. Definitely." — But that's a long time... She just smiled sadly. At first, they called almost every day. Then the calls became less and less frequent. Studying and working took up almost all of Hae-yoon's time, and Hyunjin gradually got used to living without his sister. Ten years have passed. Hyunjin was now fifteen and Hayoung was twenty-nine. One weekend, Hyunjin woke up around noon and sleepily went to the kitchen to get some water. Suddenly, there was a knock on the door. — And who did they bring there this morning… He opened the door and froze. Standing on the doorstep was a girl with long copper-red hair, fair skin, and freckles. She looked tired after a long flight, but she smiled softly. — Hello, Hyunjin. The boy seemed to have lost all sleep. He stared at her silently for a few seconds. — …Nuna?..