Iguni existed as a Jedi Padawan during the era of the Clone Wars, having received initial instruction within Yoda's classes for younglings.
Within a group that included his friend Zeami, he was among the numerous younglings undergoing training from Yoda prior to selection by a Jedi Master. During this period, he inquired whether training in the Force could amplify his strength, to which Yoda responded that while enhanced strength in the Force was possible, it wasn't guaranteed, and a weak spirit would be consumed by the dark side's flame.
By the time the Battle of Coruscant unfolded, Mace Windu had chosen Iguni as his Padawan. Despite still being a Padawan, he, along with his friends Zeami and Zoi, participated in the battle, disregarding their master's cautions. They engaged multiple B2 super battle droids and Octuptarra combat tri-droids, as well as a DSD1 dwarf spider droid. After both of his friends were injured by the droids, Iguni used the Force to create a whirlwind around himself and Zeami, destroying many droids in the process, but also harming Zoi.
Mace Windu discovered the group at this point and ordered Iguni to escort his fellow Padawans back to the Jedi Temple, citing Iguni's lack of discipline and weakness as the cause of his friends' injuries. Upon their return to the temple, Zeami received medical attention, while Zoi informed Iguni that Anakin Skywalker, the "great hero," had returned from his victory over Count Dooku. Iguni then visited the infirmary to apologize to Zeami for hurting her, but she assured him that no apology was necessary. Nevertheless, Iguni pledged to enhance his strength to safeguard those he cared for.
Iguni continued to hone his lightsaber skills under Master Windu's guidance, enduring repeated defeats with persistence. Eventually, Mace Windu acknowledged Iguni's progress, though he noted the need to maintain his guard during attacks. Despite still losing the spar, Iguni was happy to have shown some improvement.
Shortly after this, Iguni encountered Anakin Skywalker again, approaching him with a question. When Iguni asked Anakin what made him so strong in the Force, Anakin redirected the question, probing Iguni's motivation for seeking strength. Only when Iguni replied that he desired strength to protect his friends did Anakin reveal his own motivation: to protect those he loved, though he stopped himself before elaborating on the lengths he would go to for this goal.
Despite his hesitation, when Anakin touched Iguni's shoulder, Iguni experienced a Force vision depicting Anakin's fall to the dark side and his subsequent murder. Anakin Skywalker simply departed, leaving Iguni in stunned silence. Iguni's vision soon became reality, as Anakin embraced the Sith path, and it's plausible that the latter part of his vision also materialized, with Iguni being killed by Anakin himself.
Iguni's sole appearance is in the story Evil Eyes, featured in the Star Wars Manga: Black issue of Tokyopop's Star Wars Manga. Originally published in Japan, these stories were considered to have "fuzzy" continuity by Lucasfilm. They have since been re-released in English in the United Kingdom under the Infinities label, establishing their material as non-canonical.