remember Morning Star? [link]
After Akan's defeat, the demon ninja only known as "Morning Star" found no need to exact her vengeance on the man who killed her mother anymore. Pointless anger that will give her no happiness, she walked away to end her horrid life.
Until Toshi himself stopped her.
Placing her as his personal combat partner, Toshi and Sora both trained to become better warriors and masters to the lost art of ninjutsu. At the same time, she now finds happiness in her new family. Greatly forgiven by her prior wrong doings and accepted as official team member.