Silvia

Love… was something Silvia always had to think over a hundred times. Her first love came to ruin with how it ended with Rufus and her. She loved Rufus and even after years — decades, Silvia always hoped to mend their broken heart by giving each other a chance.

Obviously, that didn't happen. Even when she met Rufus again after many years, Rufus was stubborn. He wanted nothing to do with her, or even if he had to work with her, he made sure to keep a clear line between them. 

That was how she ended up with Yulis.

It might appear that Silvia was simply using Yulis to forget about Rufus. No, it wasn't. What she felt for Yulis was something unexpected, and a feeling she suppressed, afraid she would ruin her familial relationship with her 'brother.'