- Spikey-haired teenage ninjas who have a demonic partner that fights alongside them at all times, granting them the power to be considered the strongest fighters in their universes. While they started out as loud-mouthed, arrogant, and cocky, their comrades helped them to mature over time. They are descended from well-known clans of ninjas, though they are famous for different reasons, with the Uzumaki clan being well-respected and the Star clan being composed of dangerous criminals. Both are extremely determined to achieve their goals of being the best, and eventually succeed. In battle, they can combine their souls with their respective demon partners, letting them access several soul-based techniques and powered-up forms, which drain their soul energy when used, though they happen to have some of the largest and most powerful souls in their series.