Ikuto Tsukiyomi is portrayed as a mysterious and aloof individual, with a personality that closely mirrors his Guardian Character, Yoru much like a stray cat. He is often quiet, emotionally reserved, and difficult to read, yet he possesses a teasing and mischievous side, particularly when interacting with Amu Hinamori and Tadase Hotori, both of whom he enjoys provoking.

Despite his cold and detached exterior, Ikuto is deeply selfless and protective. He often pushes others away not out of disinterest, but out of a desire to shield them from the dangers surrounding him, especially those connected to the Easter Company. This is evident in his strained relationship with his younger sister, Utau, whom he distances himself from after she begins working with the Guardians. He even goes as far as antagonizing Tadase and deliberately inciting Amu’s anger to prevent them from getting involved in his personal battles.

Beneath his guarded behavior, Ikuto is highly perceptive and sincere. He has a deep emotional core and quietly values the things that matter most to him. As noted by Amu in Chapter 43 of the manga, Ikuto “loves music… and his dad”, a rare glimpse into the more vulnerable side of his character.

Ikuto Tsukiyomi is a tall and slender teenage boy with a striking appearance. He has dark blue hair and matching blue eyes, which complement his cool and enigmatic personality. He is noticeably taller than both Amu Hinamori and Tadase Hotori, contributing to his older, more mature presence.

Ikuto is typically seen wearing a black school uniform, which enhances his mysterious and rebellious image. On occasion, he dons other outfits in shades of black or indigo, staying consistent with his dark aesthetic. A distinctive accessory in his look is the choker around his neck, adorned with a silver cross, adding to his iconic visual identity.

A recurring visual trait tied to his Guardian Character, Yoru, is that Ikuto sometimes appears wearing cat ears, particularly when he undergoes a Character Change or Character Transformation, symbolizing his feline-like qualities and free-spirited nature.

Ikuto Tsukiyomi is introduced as a mysterious teenage boy under contract with the Easter Company, an organization seeking the Embryo, a magical egg said to grant any wish. Though he appears to be working for Easter, Ikuto actually harbors deep resentment toward the organization. His true motivation is to obtain the Embryo in order to gain the freedom to pursue his own wish, escaping Easter’s control and reuniting with his missing father.

Throughout the series, Ikuto frequently assists Amu Hinamori, often protecting her despite their conflicting affiliations. He is in possession of the Dumpty Key, a magical item that pairs with Amu’s Humpty Lock. The connection between these two items becomes significant in Chapters 36 and 37 of the manga, hinting at the deeper bond between the two characters.

Ikuto’s background is marked by familial tragedy and manipulation. His father, a talented violinist like Ikuto himself, disappeared during a trip abroad. After his father’s violin was found in a foreign country, Ikuto’s mother, believing her husband would never return, remarried. As a result of this new marriage, both Ikuto and his younger sister Utau were forcibly bound to Easter’s control, essentially being used by the company for its own ends.

By Chapter 43, Ikuto successfully frees himself from Easter and leaves Japan to travel the world in search of his father. In the anime’s third season, he is largely absent from the narrative, reflecting his journey abroad. Despite the distance, he remains in contact with Amu, Utau, and Tadase.

Ikuto is romantically drawn to Amu Hinamori, and his affection becomes more apparent as the series progresses. In Chapter 28, he tells Amu to “grow up faster,” expressing his wish for her to mature so she can understand his feelings. He later confesses his love for her in both Chapters 28 and 43, and kisses her on the cheek before departing on his journey. In the anime, his confession coincides with Tadase’s, though Amu initially interprets Ikuto’s words as a joke.

Yoru
Yoru is Ikuto Tsukiyomi’s Guardian Character, born from his deep desire to live freely and without constraint, much like a stray cat. Yoru represents Ikuto’s longing for independence and escape from the burdens imposed on him by the Easter Company and his complicated family situation.

Yoru is mischievous, energetic, and playful, often acting as a contrast to Ikuto’s cool and reserved personality. Despite his antics, Yoru is deeply loyal to Ikuto and often shows genuine concern for his well-being. He frequently appears perched on Ikuto’s shoulder or head and occasionally interacts with other Guardian Characters, especially Amu’s trio.

Physically, Yoru resembles a miniature, chibi version of Ikuto, with dark blue cat ears and a tail, along with yellow eyes and a small feline fang. He wears a small hoodie with a collar and a bell, further emphasizing his cat-like nature.

Yoru plays a central role in Character Change and Character Transformation, enabling Ikuto to take on his alter ego, Black Lynx, which enhances his agility and grants him claw-like weapons used in combat.

The name Ikuto (イクト) is written in katakana, which does not convey a specific meaning in Japanese but gives the name a modern and stylistic tone.

His surname, Tsukiyomi (月詠), is composed of the kanji 月 (tsuki), meaning “moon,” and 詠 (yomi or utau), meaning “to recite” or “to chant.” The name may be a reference to Tsukuyomi, the moon god in Japanese mythology, symbolizing darkness, mystery, and solitude all traits associated with Ikuto’s personality.

The lunar imagery present in both his name and character design aligns with his nocturnal, cat-like motif and the themes of freedom and secrecy that define his role in Shugo Chara!.