The Two's Pasts - S1.E15

Joh-on's son comes and asks his father to become a teacher again. When his son learned that his dad had a young girl living with him, he offered to have her come live with them and have Erin marry-off. But Joh-on decides that he's happier with Erin and asks his son to deliver a letter to an old friend at an Ohju breeding school.