Izumi Uchiha was a kunoichi from Konohagakure and a member of the Uchiha Clan. She was a friend of Itachi Uchiha since their childhood and deeply cared about him, being so close to him as to be seen as his lover.
In the manga, Tobi mentions Itachi had a lover, who is later revealed to be Izumi.
Her father was not an Uchiha and died during the Kyuubi attack. She awakened her sharingan after witnessing his death.
Izumi and Itachi bond over their shared dream of peace and enjoy one another's company.
During the massacre, Itachi visits Izumi first and shows her a Tsukuyomi dream lasting more than seventy years. Itachi's dream for his girlfriend shows the two living in peace with both the Uchiha clan and Konoha, their marriage, raising their children and finally him taking care of her in her old age as she passes away. Izumi dies in Itachi's arms peacefully, thanking him for the dream. Itachi thanks her for loving him.
