The Third Ending

Seo Yoon Seul, who's lived a perfect life so far, becomes a wreck when he starts having nightmares of a boy whom he coldly rejected when he was a student. The nightmares get even worse when he reunites with Kang Joon. Following his advice on becoming a good person to avoid nightmares, Yoon Seul approaches him to win his favor. Note: from season 2 (chapter 36) this becomes Mature (R19), Season 1 is All-Age (R15) Note: Chapter count includes a 3-chapter side story and 2 episodes that were a Christmas special