A wrench was suddenly thrown into the the harmonious and peaceful lives of Choi (YN) and Minatozaki Sana, two housemates that were the complete opposite of each other. The peace and quiet that always existed in their shared apartment was suddenly turned into the cries, wails and shrieks of a child they found outside of their home on one faithful night. Having been involved with many problems before, the housemates now try to find a way to live with their new baby problems.

Jihyo found Baby Y/n in an alley on her way back to the dorm. She took her back home, and they all agreed to take care of her.

When Lisa turns into a kid, will the rest of Blackpink be able to handle her? And will they be able to turn her back to normal before time runs out?