No.1 Uchiha Fugaku: Itachi's father, Fugaku, was his first ninja teacher and taught him more than just ninjutsu. Fugaku's teachings influenced Itachi's loyalty and choices. Before his death, Fugaku emphasized the importance of respecting one's choices.

No.2 Suigetsu: Suigetsu was Itachi's upper-level ninja teacher. Though not very strong, he played a significant role in Itachi's development, akin to Iruka's influence on Naruto.

No.3 Uchiha Shisui: Shisui, Itachi's close friend and Uchiha clan genius, had a major impact on Itachi's mindset and taught him various ninjutsu techniques. Shisui gave Itachi his Mangekyou Sharingan before dying, influencing Itachi's subsequent decisions.

No.4 Hatake Kakashi: Kakashi, older and experienced like Itachi, was his comrade in the Anbu. Itachi sought advice from Kakashi about trust. Kakashi advised him never to betray his friends' trust.

No.5 Zabuza Momochi: Zabuza, Itachi's comrade in Akatsuki, sacrificed his life to protect Itachi during a mission. This event made Itachi realize his mistakes of shouldering burdens alone and influenced his decision to emphasize the importance of comrades to Naruto.