Personally, I think Sakurano actually has a strong inside (refer to the episode where Ryoma's eye was injured). Maybe it's because of her environment or education issues that made her seal the wildness (?) In her heart. I'll let her slowly become stronger here!
There are original characters, but they won't fall in love with the princes.
The story is probably: Sakurano was changed and ended up with Ryoma. (I know this introduction is very irresponsible, but I am really incompetent...)
PS. The deputy CP is Tsuka Fuji.
PS. The PS. Will look a lot like Sakurano and the original character Yuri at first, so please proceed with caution.