Niana (short story)

This is a short story about two siblings who didn't know how to deal with each other. Ranz Kyle, who was the older brother of Niana, felt jelous and intolerant for his younger sister. When his sister came to their family, his parents always look at Niana's attention. Would Ranz accept the fact that he has a responsibilities to take care of Niana or he will not treat Niana as a younger sister for the rest of his life?