Stealing became the middle names of Momo, Sana and Mina. After their parents died in Japan, they were sent to the Twice Orphanage in Korea but it's not like what they've imagined. Now, they've been given a mission to steal the heart diamond in the Royal family's mansion but it seems like their hearts are the ones that's been stolen.

In which an innocent and kindhearted boy struggles to deal with his lifelong deafness. Not because being deaf is hard, but because bullies torment him. He feels alone until someone new comes into his life and makes him feel like he can hear everything

Mute... "refraining from speech or temporarily speechless...."