I'm the Brave Puppy Who Came to Save the Villainess Sister

My name is Coco. I'm a wonderful puppy with fluffy white fur. "If there's a next life, please be born as my sister's daughter. Okay?" I had a happy dog life with my sister and crossed the rainbow bridge. ...Why does everyone hate my sister?' No! My sister's happy life is protected by a brave puppy! ...And so I crossed the rainbow bridge again and was reincarnated into my sister's family as a five-year-old adopted daughter. But becoming close to my sister isn't easy at all. "Don't call me 'sister.' You're not my sister." It's okay if my sister doesn't recognize Coco. This time, I'll approach you first. "I just wanted to be close to Chloe." So, can you be close to me again? (Source: Kakaopage, translated)