The Extra Little Sister

"You can take on the identity of a younger sister, but you can't use that identity to gain your older brother's love and trust. You will be strangers who are closer to each other than anyone else. This is where you start. Do you accept that?"

The girl slowly gave a faint smile, her eyes lowered.

"I can't refuse. Otherwise, I'm afraid that person would be too lonely. This is the duty of a Lingyu, isn't it? When you hear a call like that, you can't help but strive to answer it."

Theme: A call answered.