~Prologue~

Y/N Corbeaux Noirs, the only child of the war hero and the flower of society who has a calm personality, no one can tell what is going on in her mind. She went to the birthday princess of Elmir Empire and meets a brother who loves his sister so much.

Y/N Corbeaux Noirs being an only child that has never talked to that much people and stayed in the library all the time found this interesting.

So she wanted to befriend this brother who loved his sister so much and know about this sibling love more

But, Will they be only friend?