Su (スゥ, Su) is Amu Hinamori's third Guardian Character. She represents Amu's desire to be more caring and improve her domestic skills. Her fellow Guardian Characters are: Ran, Miki, and Dia. Her name coincidentally is the same as the second syllable of "desu", which she says after most of her sentences.
Su's outfit resembles a waitress or a housemaid, with a typical white apron and a frilly, green dress under it with green shoes with laces that cross to create an "x". She has emerald green eyes. Her light green hair (though mainly appears to be blond sometimes) is short (or possibly tucked into her hat) in the back and grows longer in the front, where it ends in delicate curls. On her hat, a clover symbol is attached. Once in Shugo Chara! Pucchi Puchi!, Su lost her Clover, so her, Ran, Dia and Miki looked for it. Luckily, Kusukusu and Pepe found it.
Su is very gentle, orderly, girly and laid back, with a motherly attitude towards people who need care. But she can also be quite clumsy and ditsy at times. She is one with the most interaction with Yuu Nikaidou after helping him clean his room. She has fear of insects like caterpillars, though she can get scared of anything relatively easily. Sometimes she can be over the top during cleaning jobs, ordering others around to help out. However most of time she is extremely polite, to the point that she refers to the Embryo as 'Embryo-san'. The Shugo Chara Encyclopedia describes Su as an "excellent cook", but "a spontaneous girl with her head in the clouds".
- In the anime television series, Su is voiced by Aki Toyosaki.
- In one episode, Su counts flowers to see if someone loves her or not. In Episode 90, when Yuu Nikaidou and Yukari Sanjou were in the Love-shout contest, she said "Even if it makes me sad, I hope for his happiness." Many fans assume she is in love with Yuu Nikaidou, but that has not yet been confirmed.
- Su has the most interaction with Yoru out of Amu's Shugo Chara. Yoru constantly plays pranks on Su, they are seen close when flying together, and Yoru saved Su in an episode.
- She gets along well with Ran, Miki, and Dia. Su shares friendships with Kiseki, Temari, Daichi, Kusukusu, Il, El, Yoru, Musashi, Rhythm, Nana and Pepe.
Su's name was simply translated as "silk" in Japanese.
The second reference is that Su's name is coincidentally identical as "desu".
- Amu's guardians represent the four playing cards: Hearts (Ran), Spades (Miki), Clubs (Su) and Diamonds (Dia).
- Su ends almost all her phrases with "-desu", which is used to make a sentence polite.
- Su is constantly associated with Suiseiseki from Rozen Maiden, another series by Peach-Pit because they have green as their theme color and both end their phrases with "-desu".
- Su usually speaks in third person.
- In the "Lotta Love Lotta Love" ending, she had a drum set with a clover on it.
- When in the transformation Amulet Clover in the manga, she never performs "Open Heart", but instead uses "Remake Honey." However she only uses open heart on ? Eggs.
- Amulet Clover has the most upgrades.
- According to Peach-Pit, Su's name was influenced from Candies member, Yoshiko Tanaka, who was known by the nickname "Sue".
- In Shugo Chara! Pucchi Puchi! Su put a X-Mark on her Clover then she began to cook poisonous food and she spills anything.
- The name Su litirally translates to 'Be'.
- "Leave this here to Su." (Episode 3).
- "You are from a world Su will never understand." (Episode 55), after telling Il and El that she cleaned Yukari Sanjo's office).
- "Thank you very much for coming to see Su today! By the way, the girls behind me are Miki and Ran." (Pucchi Puchi Short 1).
- "The prince's ice cream- it's an indirect kiss!" (Episode 33).
- "Keep reinventing and polishing yourself, and who you want to be can be reborn over and over." (Episode 23).