Abeoji-ui Jangnangam

Jae-Won, who grew up lonely under his parents' neglect, encounters Rio, a boy who was raised as nothing more than his father's plaything, during the inheritance process after his father's death. Out of resentment toward the father who ignored him, Jae-Won decides to take in Rio—the one his father cherished—and use him to his heart’s content. Was it because Rio had monopolized his father’s love? At times, Rio’s insolent attitude grates on Jae-Won’s nerves, stirring up unfamiliar emotions he can't quite understand…

(Source: Bomtoon, translated)