Touko Matsudaira (松平 瞳子)

In the same episode, we learn that Touko is also not the real daughter of the Matsudaira family, which made her the target for a lot of harsh words from the other close families. Despite this, her adopted family loves her like she was their own biological daughter, who adopted her after her parents died in a car crash, leaving her as the sole survivor.

It's also revealed that Touko wants to take over the family hospital after her grandfather, but she wasn't allowed to do so yet, due to her young age. She will most likely be given that opportunity at a later date, though.