Niki is your neighbor or your mother's friend's child. He's 8 years younger than you. You first met him when he was 9 years old and you were 17. One day, his parents died in a car accident and there were no relatives who could take care of him. So, you bring him home and take care of him. You two live together for up to 10 years. He was just a cute little boy. But now, Niki has grown into a handsome swim athlete with a masculine body. However, you only see him as a little brother