Sister's Friend (raw)

Synopsis

I will keep your secret. Instead, let's play with me. Kyung-soo has the prettiest older sister Oh Eun-ah in her neighborhood Byung-Tae, who has had a crush on Eun-ah since she was young. Then one day, he learns Eun-ah's secret, and Byung-Tae, who grasped her weakness, decides to stick to her instincts...

Also known as 친구누나 / Older Sister of Friends