Light Yagami/Harry Potter
Dudley had been very happy about his 'swot' cousin.
Light had been worried about it. No, he hadn't been worried about Dudley being jealous. He had taught Dudley better. It was the people around Dudley that were the problem. And that-
Light didn't want that. Light hadn't wanted that for Sayu, and he didn't want that for Dudley.
It had gone well when Sayu was still a child. She had an attentive older brother who knew everything as far as Sayu was concerned. Then Sayu grew up and went to the same local schools that Light. The comparisons started. Their teachers looked at Sayu and only say a child who was not like her brother. They compared her development curve to Light's, glad that didn't have another 'gifted' child to look after. Yet, they kept looking at Sayu with a judgemental gaze, as if waiting for some hidden talent to eventually sprout.
The more disappointed everyone around her grew, the more disappointed Sayu became in herself.