A boy who wants the Embryo to obtain his freedom. During Character Change, he grows cat ears, and his hand turns into a paw with metal claws. His Character Transformation is known as "Black Lynx". During Character Transformation, he uses a claw-like glove and wears a leather 2-piece with boots.
His Shugo Chara is Yoru and has the form of a cat. This could possibly be because Ikuto wants his freedom and cats are free.
He is actually 5 years older than Amu and Tadase, as he told Amu on chapter 28 that he was going to be a 3rd year senior and she was just starting middle school.
At first he is called "nekomimi hentai cosplay otoko" ( lit. perverted cat-ears cosplay guy) by Amu. Ikuto has sensitive ears, like Amu. He possesses the "Dumpty Key", which is the other pair of the "Humpty Lock" owned by Amu. For some unknown reason, Tadase had the key and Ikuto stole it from him. When Tadase confronts him about it on episode 28, Ikuto tells him that he was taking something that was actually his. He is Utau's elder brother and he refers to Tadase as "Kiddy King."
It's revealed in chapter 25 or 24 and 17 of the manga that Utau, Tadase and Ikuto were childhood friends. Tadase called him "Onii-Tan".
He signed a contract with Easter and is looking for the Embryo, an egg that will grant any wish. Its because of that he becomes an enemy to Amu, but privately he helps Amu in the shadows. In the latest chapters, his relationship with Amu has taken a turn for the better. He has even said that he is "interested" in her.
In episode 29 Utau says to Amu that Ikuto likes Amu. And in chapter 28, Amu asks him if he has someone he loves and he answers, "It's you". She takes it as a joke but when Utau tells her that he was not lying, she realizes that Ikuto was being honest. In episode 29/chapter 18, Ikuto was kissed by Utau, in reaction to that Amu starts freaking out until she hears that Ikuto in no way returns her feelings and to him all they, he and Utau, are, are siblings.
Like his father, Ikuto can play the violin.