Promises (Seventeen fanfic)

After the death of her parents, Eun Hye has never let go of the promise she made with her mother:
"That whoever you meet and care about, to protect them with all your power and to love them forever."
To protect the sons of her parents closest friends, she allows them to live in her home, at the cost of not letting them know she exists.
Watching them from afar, she sees and hears things that nobody else would. As time goes by, keeping her distance becomes harder as trouble arises.