It's an Honor to Be in Charge of Teaching

MV Mulsan's only son, Jae-Won, unfortunately has no interest in business and wanders around. His father, who dislikes such Jae-Won, takes in Han-Jin as his adopted son, offering to pass down the company to him. Jae-Won asks about this and that in an unexpected situation, but no one gives a proper explanation, and Han-Jin answers with a kiss, confusing Jae-Won...?!

(Source: Mr.Blue, translated)