After Rebirth, I Will Be the Eldest Sister to My Female Counterpart

In his previous life, he was unlucky. He was kicked into the lake by his female counterpart and drowned. The girl who was born as a female partner also got a chance to save people, and she was able to get along like a fish in water in the capital. She was reborn by chance and became the heroine's sister. I'll take my revenge myself. But one day she discovered that there was something strange about her life experience. But the person who could never be with her stayed with her throughout her life.