The Ueno Clan is one of Senjokuni's most prominent freelance shinobi clans. Though they serve no particular lord, they traditionally have a standard of who they'll accept missions from. The Ueno have a strong sense of justice, and won't assassinate anyone nor for anyone that violates this code of honor.
At least, that's how it was before their home was attacked by one of the country's most powerful warlords, Nagataka Ogata, who feared the shinobi's power. Desperate to rebuild the clan, its leader, Hanzo, lifted the standard against less honorable assassination requests in hopes to bring in more revenue. This led to a falling out between him and his niece, Hikari, who opposed this decision and challenged him for leadership. She lost, resulting in her banishment.
Currently, the clan is still recovering and still keeps its usual standards on hold.