Geu Jip Gangajiga Gwiyeopdamyeonseoyo?

So-Eon takes care of the dog 'Mango' in place of her brother who is overseas on a business trip. She brought him home without much thought... but there are too many things to worry about, such as walks, food, and toilet use. Then one day, while walking, she accidentally loses Mango! Luckily, someone catches Mango and returns it to So-Eon... But...