After Sun-Young misses a proposal deadline and gets Ho-Jun reprimanded by his superior, he takes punishment into his own hands. During overtime, he spanks her and orders her to wear a vibrator for a full day.
Sun-Young asks her superior Ho-Jun to train her in a Master-Slave BDSM dynamic. His first command is for her to wear a vibrator while walking around. His second command is for her to perform oral sex on him under a table. She keeps his ejaculate in her mouth for the remainder of the workday, which immensely satisfies him. He then rushes her home for an intense sexual encounter.