Rebuilding A Shredded Heart

(A/n: my first time doing an NTR story, but it will be my Oc doing it rather than getting it)

A young man had a normal life, but when his father died, his mother abandoned him and his little sister with someone she had never met. So he leaves with his younger sister, raising her by himself when he gets a girlfriend, she too did the same thing. as his mother ditching him for someone else, but shotaro promises himself that when he'll become strong and he will do anything to protect his little sister from from anyone who will try to hurt or take advantage of her.