The Blurred Lines Between Us

With a perfect older brother, Yim Juhyeong's inferiority complex has always driven him to be better than other people. Everything goes well until a new transfer student named Yim Seon shows up. Despite being superior to Junhyeong in every single way, Seon, for some mysterious reason, seems intent on devoting himself to taking care of Juhyeong. Even though Junhyeong should hate it, he doesn't understand why he can't push Seon away. Source: Lezhin Includes 3 extra volumes.