Kimi ni Todoke Bangai-hen: Unmei no Hito

With her jet-black hair, sinister smile, and silent demeanor, Sawako “Sadako” Kuronuma always had trouble fitting in during high school. But with help from her friends, her boyfriend Kazehaya, and even her rival-turned-friend Kurumi, Sawako came out of her shell. Now in college, Sawako and Kurumi have become incredibly close, but Kurumi longs for a romance of her own.
Despite considering herself unlovable, and despite feeling deeply satisfied with Sawako’s companionship, Kurumi decides to put herself out there and try dating. When she’s pestered by a persistent suitor after a party, a handsome stranger comes to her rescue. He looks suspiciously like Sawako…or not so suspicious, considering that he is actually Sawako’s cousin! When Kurumi starts to feel drawn to him, could it be love?
(Source: Viz Media)