she is the rich granddaughter of a powerful family
he lost the ability to hear or speak so the lady acts like she cannot hear or speak to help him not feel insecure
she communicates with him using sign language
but in reality she can speak and has a beautiful singing voice but due to a scheming woman's influence he starts to treat he coldly and so she with the help of her powerful grandfather takes her revenge on him the scheming woman and his mother since they all have been rude towards her
the scheming woman made it like she was either pregnant with his kid or his brother's kid but that was a lie it was really some random guy's kid