Ding-dong, ding-dong-ding-dong, ding, dong. Ding-dong, ding-dong-ding, dong-ding, dong.

It was late at night. An old-fashioned doorbell rang ominously in the old building.
Worried that the neighbors might be bothered by the annoying noise, Ji Hee-jin cautiously opened the front door, wondering what was going on.

“Who is it…?”

“Noona. Long time no see.”

Ji Hee-jin and Ji Hyun-woo, who had been step-siblings for five years due to their parents’ remarriage, were reunited after five years.

Hyun-woo, who had returned home in triumph as a successful medical student, approached a drunken Hee-jin and whispered to her that this time, they should become a family, not as siblings, but as a married couple…