One day, Yun-Hyeok suddenly finds himself with a younger brother—Yun-Jae, a sickly child diagnosed with an incurable disease. Determined to protect him, Yun-Hyeok takes on the role of Yun-Jae’s guardian, raising him with unwavering devotion for the next 15 years. But as Yun-Jae grows older, he begins to push the boundaries of their sibling relationship. Then one day, through the security cameras Yun-Hyeok installed to keep an eye on Yun-Jae, he witnesses something he was never meant to see…

(Source: Lezhin US)