Rhythm (リズム, Rizumu) is Nagihiko Fujisaki's second Guardian Character. He represents his liking of basketball. His partner is the elegant, yet fierce Temari, who went back to her slumber before Nagihiko returned to Japan. At the same time, his egg was created before Nagihiko returned to Japan and is seen in Chapter 30 and Episode 56 of the anime. He hatches in Episode 91.
Rhythm appears with long violet hair that reaches to his waist. He wears a baby blue beanie, long-sleeved shirt, blue vest, and jeans. On his feet are white shoes and blue soles. Around his neck, he has a pair of blue-black headphones.
- In the anime television series, Rhythm is voiced by Kouki Miyata.
He is born from Nagihiko's boyish self, so he is cool, outgoing, and a flirt. He is shown to like basketball, like Nagihiko when he was little. Rhythm is described to be friendly by Yaya, enthusiastic by Tadase, a flirt by Rima and one that acts impulsively by Nagihiko. The Shugo Chara! Encyclopedia! describes Rhythm as "full of energy" with a "'just do it' attitude". The female Charas, especially Miki, seem to have a crush on him.
When Rhythm Character Changes with Nagihiko, Nagihiko gains a pair of headphones around his neck as an aspect to his change and becomes more sporty and outgoing to an incredible point, making his athletic abilities comparable to both Amu and Kukai in Character Change.
In Chapter 34 of the manga and in Episode 91 of the anime, when Nagihiko is reminded of how much he liked baskbetball when he was younger while fighting with the X-Characters, he triggers the birth of Rhythm and they undergo a Character Transformation, becoming "Beat Jumper".
- "I definitely heard it. Your rhythm." Episode 91 (before hatching)
- "I'm Rhythm. Now, let's go!" Episode 91 (after hatching)
- "Feel the beat! Ride the rhythm! March to the beat of my own drum!" (episode 92)
- "So Ran, Miki, Su... You're all with Amu? I like your rhythm. You're all so cute!" (After first Character Transformation)
- "Temari, I'm subbing out." Episode 99
- "You girls rock!" Episode 99 (to Temari and Kusu Kusu)
- "Yay!" Episode 92 (During Charachange with Nagihiko)
- "Make it cool!" Episode 92
- Though Rhythm is Nagihiko's second Guardian Character, he is the first one to perform a Character Transformation with him.
- In addition, Rhythm is the second Guardian Character to perform a Character Transformation with its owner moments after hatching, the first being Ran.
- Whenever Rhythm character changes with Nagihiko, Nagihiko uses ore instead of boku.