Douluo: Tang San Forbidden Harem (18+)

To understand the bond between Tang San and his sister, we must go back to when Tang San was six years old. After he was diagnosed with twin martial souls and innate full soul power, he was recommended to study at the Notting Junior Soul Master Academy.

There, he met Xiao Wu, who shared a dormitory with him. The two initially clashed but eventually became best friends. After more than a year of studying together, their relationship grew closer, and Xiao Wu secretly harbored feelings for Tang San.

Tang San also developed a deep affection for this lovely girl. Although she was nominally his sister, a deeper affection inevitably developed between them, as one day his sister Xiao Wu said "elder brother!
Shall we shower together?
Xiao Wu blushed slightly and said timidly.
"What?"
Tang San was genuinely surprised. Men and women shouldn't touch each other. Although he was only 12 years old, he had lived two lives and was already an adult.
Xiao Wu's suggestion really put him in a dilemma!
Watching his sister slowly take off her clothes with her back to him, he knew it was too late for her to refuse!
And there's no reason to refuse, but his sister is already 11 years old and starting to develop. How can he take a bath with his sister?
But then he remembered that she was his sister, and there was nothing strange about taking a bath together; they were both still children.
When he saw Xiaowu lift her feet and pull her underwear down to her feet, he noticed that his sister's bottom seemed to have grown bigger, rounder, and whiter. The cleft between her thighs was no longer just white; a faint red line revealed an aura that only a little girl could possess.