He ends most of his sentences with "~nomi."
Shut has pale blonde hair, green eyes with blue makeup underneath, blue lipstick, and wears a white hat with blue roses and a blue feather on the side. He also wears a suit with flaring sleeves and white ruffles, and also blue fishnet stockings and long boots. He wears a lock similar to Close's on his neck like a brooch. Additionally, he is usually always seen carrying a blue rose. He also has fanged teeth.
In his beast form, he resembles a large lynx-like creature with light yellow fur and red eyes with dark blue markings under them.
In episode 50, he now wears a bright blue suit and shorts with a ruffly white shirt underneath. He also wears black fishnet stocking and heels. His hair is now in a bun and his makeup is now the same as in episode 33. He now wears Lock, who is now a black and yellow-striped scarf.
Shut adores everything that is beautiful but considers dreams as pointless. He is a narcissist and also pompous. When suffering from a loss against the Pretty Cure, he can be a sore loser as well.
Unlike Close and Lock, he seems to be timid and easily scared, and this trait is shown on various occasions; when Twilight was defeated and turned back into Towa, he acted horrified and shocked as if something very tragic had happened. When Lock later powers up and resorts to more dastardly and sinister plans, he cowers in fear.
When he interacts with others, he mostly puts up a rather cold and hostile attitude. But occasionally, when meeting somebody (namely Miss Shamour) who treats him kindly, he can come across grateful. He likes presenting himself in a fancy, feminine way, and he ends up bonding with Miss Shamour over this.
- Twilight - When he first sees Twilight, he seems to be charmed by her beauty, to the point in which he feels jealous when she powers up Lock instead of him. He is always seen blushing or admiring her when he is around her. After Twilight is purified, Shut becomes devastated, and in episode 25, he learns that she now goes under the name "Akagi Towa" and is also Cure Scarlet. Though he still finds her beautiful, at the same time, he wants to defeat her.
- Lock - At first, Shut thinks of Lock as an annoying kid who just gets in his way, but as the episodes progress, and Lock becomes more powerful, Shut begins to be more afraid of him and sees him a lot differently.
- Miss Shamour - Shut seems to have a good deal of respect for her as she was the first to show any kindness towards him, by helping him with his makeup and then by giving him a scarf to keep him warm after he leaves on his own. This seems to be what influenced his decision of leaving Dys Dark as he is seen wearing the scarf when he returns to help the Pretty Cure.
- Close - Shut has a poor relationship with Close, owing to the latter always abusing him cruelly. On the surface, he pretends to obey Close, but deep down, he actually bears a boiling rage against him.
Shut made his formal debut in episode 3, fighting alongside Close. He meets the girls in person after taking over a karate boy's dream and turning it into a Zetsuborg, which he commanded to attack. However, after Close arrives with his own Zetsuborg, the two begin to argue over who should attack whom, buying Flora and Mermaid enough time to finish off their Zetsuborgs, forcing them to take their leave after their defeat.
In episode 7, Shut appeared at the tennis match and considering Aihara Yuuki's dream of playing tennis dumb, he corrupted Yuuki and turned the latter into a Zetsuborg. But once again, he was defeated after Mermaid and Twinkle came to Flora's aid.
In episode 12, Shut appeared at the finished race between Kirara and Ichijo Ranko. In the beginning, he mistook Ranko as a comedian and was puzzled by Ranko dreaming about becoming a top-class adorable idol, but he still sealed her dream away as he found it stupid. He suffered from defeat after the girls purified his Zetsuborg.
In episode 13, Shut accompanied Twilight for the first time when the latter used her black Dress Up Key to power up his lock, which he used to target Nishikido-san as his victim, locking him and making a violin Zetsuborg, but the Cures end up saving him.
He also accompanied her in episode 14, admiring her grace and music, though Twilight appeared to have no interest in his admiration. He later trapped the Haruno family into cages and created a Dorayaki Zetsuborg but lost again after Flora was determined to save her family. He was bitter about the loss and went on to attack the Cures until Twilight called him out for being a sore loser, and he desperately trailed behind her as she stormed off.
In episode 17, Shut went with Twilight at the fashion show and he targeted Amanogawa Stella, using her strong dream to create two model Zetsuborgs at the same time. However, he lost when Twinkle's tight bond with her mother allowed her to obtain a new Dress Up Key, which incapacitated the Zetsuborg enough for the three Cures to purify and save Stella.
In episode 20, Shut and Lock confronted Mermaid and Twinkle respectively as the two Cures were wandering to the castle of Hope Kingdom, but the girls end up distracting them. Then in episode 21, he was astonished and horrified to witness Twilight turning back into Towa, realizing that she wasn't the beautiful Black Princess he had an obsession on.
In episode 23, Dyspear had enough of him constantly losing to the Pretty Cure, and demoted his position so that he would no longer have the authority to go on important missions. Later in episode 24, Shut was astonished by how Lock had aged and wondered what possibly happened. While Lock remained casual and refused to acknowledge his change, Shut still insisted as he knew that he had been replaced by Lock.
In episode 25, Shut was humiliated by Lock, who added salt to his wound of losing his crush for Twilight during their boat ride. When he noticed Towa's happiness, he was fueled with anger and summoned a Zetsuborg from the leader among a group of volunteer firemen. He then openly expressed his jealousy towards Towa, and even when Minami tried to convince him that Towa was not Twilight anymore, he refused to accept the fact. He was once again left humiliated after the Cures finished off his Zetsuborg with their teamwork.
In episode 26, he was wandering Noble Academy, depressed that there was no person vulnerable enough for him to gather despair when he spotted a cicada. He took advantage by turning the cicada into a Zetsuborg, though it was particularly useless. When he noticed Pafu was trying to capture the cicada Zetsuborg with a bug net, he became really annoyed by her antics and tried to attack her with the insect until Aroma arrived to protect Pafu. He soon witnessed the fairy siblings gaining their new forms, and then faced a painful defeat from the Cures before storming off.
He did his mission on collecting despair and turning victims into episode 27, this time targeting Yuki's fangirls and summoned three Zetsuborgs in return. But thanks to Yuki who helped the Cures by using a rock to knock the Zetsuborgs off guard, his plan was foiled.
In episode 29, Shut was startled to find three Lock clones, each holding three keys. He could only helplessly wonder what happened as Lock reveals that although he's still missing some of the keys, he has more than enough. When Lock threw the brand new lock at the Hope Kingdom's castle, it lifted itself up from the ground and turns into a grand Zetsuborg, much to Shut's surprise.
In episode 33, Shut was abused by Close who caught him putting on makeup, and his mirror was shattered as punishment. He then met Miss Shamour, Kuroro and the girls, and became extremely envious of them being able to have nice clothes and makeup, thus he targeted the black cats and turned them into Zetsuborgs. Just as he was about to attack Yui and the fairies, Miss Shamour stopped him and after a small combat between them, she decided to give him a makeup lesson to help him feel better. After having a huge makeover, he was still amazed by his own makeup and left the scene. He even showed his new look to his colleagues when he got back to the Dys Dark lair.
After having failed to accomplish Dyspear's ultimatum for him in episode 45, Shut was seen wandering on his own in episode 46, as he was afraid to be executed by his boss. When he noticed the girls building a snow castle, his grudge towards them finally exploded and the power of despair turned him into a fierce lynx-looking beast. After the Cures purified him, Cure Scarlet tried to persuade him to turn over a new leaf, but he coldly rejected her and left with the scarf Miss Shamour gave him.
In episode 48, after witnessing Close's resurrection and how he controlled Lock, Shut recalled how Close used to abuse him as well, so he decided to help the Cures by briefly stopping Close's attack, even though he got overpowered afterwards. He also begged the Cures to purify Lock. In episode 49, he and Lock assisted the Cures by buying them time through intervening with the vines Dyspear created.
After the Cures' final battle with Close in episode 50, Shut no longer had his powers and therefore had stayed in the human world, with Lock now possessing his scarf. He then met Mochizuki Yume and Shirogane-san when he was in the rose garden, and was last seen shyly and awkwardly greeting them.
Like the rest of the Three Musketeers, he can trap people into a gate of desperation to create Zetsuborgs. To trap people in the gate of desperation, he says "Shut Your Dream!" (シャット・ユア・ドリーム！?). In episode 20, it is shown that he can fire lasers from his rose. He can also slash through anything with his claw-like nails.
Shut's voice actor, Hino Satoshi, has participated in an image song for the character he voices. This duet is only sung with Madono Mitsuaki, who voices Close, and Kaida Yuki, who voices Lock.
- Perfect Black (Along with Madono Mitsuaki and Kaida Yuki)
- Like the other members of the Three Musketeers, his name refers to sealing something away.
- Shut's favorite flower is the rose, as it reminds him of his past crush towards Twilight/Cure Scarlet.