Shimon Ikaruga (
He has spiked fuchsia-colored hair that starts after his headphones and azure blue eyes. He wears a dark maroon shoal that tatters at the ends, topping a black shirt with a white circle that's crossed by a line. His lower clothes consists of cargo shorts, and black combat boots. He can sometimes be seen with his exorcist uniform on duties. He is described as handsome by girls throughout the series.
Following his fight with Tenma Unomiya, Shimon lost his leg. During the Yuto suppression mission, he has recovered from his injuries and is given a prosthetic leg.
Compared to other characters, Shimon is very serious and cold. His focus consists of defeating all the impurities instead of hanging out with others teens around his age. It is later revealed that his devotion to killing Impurities is because he is trying to put an end to the one-thousand-year war and break Sayo's heavy burden so she can live a free life from the Kuzunoha. This devotion has caused him to gain a form of arrogance; initially belittling Rokuro during their fight and thinking that he alone can achieve his goal.
Shimon becomes sensitive but pretend to ignore them when it comes to some female charms, as shown in the anime when he slightly loses his cool when Mayura tripped over a string, causing her to lose balance and accidentally lean her chest to his forearm, and in the manga when he loses control of his Crimson Phoenix wings when Mayura unintentionally leans her chest to him.
Shimon suffers from motion sickness, this was shown in chapter 33 when Shimon is upset for flying back to pick Rokuro up. He explains that the plane does not move as he want it to. On the ship back to Tsuchimikado Island, and another one on the training trip with Mayura, he is nearly vomiting. He needs to take pills before enchanted with Crimson Phoenix, as the SD As Imperative Order!! shown.
Shimon's hobby is cultivating potted plants. He also likes to collect earphones, having 12 of them.
Shimon used to be part of a branch family until he lost his mother to an illness immediately after being born, and his father died in battle in Magano when he was three. He was later adopted by the head of the Ikaruga House, Hoji Ikaruga. He was considered as a child prodigy, and became one of the Twelve Guardians at the age of 14.
His relationship with Rokuro is of comrade slowly starts. He develops respect for Rokuro when he came to his aid after the Basara who wants to kill Sayo for power. After both saving Sayo and defeating the two Basara with him, Shimon kneeled down to Rokuro thanking and saying, that he is honored to have been able to fight alongside as a comrade.
Shimon later bore witness to Rokuro's battle against Kankuro Mitosaka and was surprised by his Shikigami's form. However, he was by the transformation into gauntlets and how he overpowered Kankuro. Shimon internally questioned Rokuro's rapid development since their last fight.
When the first match ups have been decided, Shimon's opponent is Tenma Unomiya and their match will be the 10th fight of the first round of the tournament. In the match, he held his own and showed off some of his new techniques but his opponent overpowered him and used his enchanted gear and cut off Shimon’s leg.
After the games, Shimon was hospitalized while Tenma was made to apologize to the Ikaruga House and was put on house arrest. He was visited by Keiji who stepped out to let Shimon talk to Mayura while teasing them. Mayura comforted him on his lost. Tenma later visited the hospital, where the staff were shocked to see him before he approached Shimon's room and was casual at his and his brother's shocked faces. Tenma was grabbed by Keiji Ikaruga who condemned him for cutting off his brother's leg and threatened him but Shimon broke it up. However, Tenma's taunts led him to be punched by Keiji. After Shimon had Keiji leave, Shimon told Tenma that he knew he held back. Tenma was irritated by this deduction as well as Shimon telling him he doesn’t want the secrets of the mission, since he didn’t feel he won. Eventually, Tenma got him to listen.
When a group of exorcists consisting of Mayura, Keiji Kankuro, Kengo, and other exorcists arrive at Magano Depth 2013, where they find the defeated Tenma. After making sure that Tenma is alive, the group decides to head to where Rokuro is fighting Yuto, when the Basara Shioji appears, along with the rest of the Impurities that escaped to Magano, who get fused in a massive Impurity with a spell. However, before an attack reaches them, the Impurity's arm get destroyed by Shimon, who suddenly arrives at the scene.
It is shown Shimon has been given a prosthetic leg and has recovered from his injuries. Seeing this, Tenma remembers when he told the reason that he told Shimon that he cut off Shimon's leg was to prevent Shimon from joining the fight against Yuto. Tenma had foretold that, just like him, he would die during the fight the way he was. Tenma wanted Shimon to stay away from the fight, and guide the Twin Stars in his stead. Keiji declares that even if Tenma cut off his legs, he would never have affected his conviction.
In the anime, he was summoned by Arima to find Rokuro. He saved Rokuro and Benio from a demon and shortly after left and went back to Arima, and said Rokuro is not strong and does not care about him. However, late in one fight, he saw Rokuro's abilities, when he saved everybody from an explosion, and eventually made friends with him. In addition, Shimon trained Mayura in becoming an exorcist and they are said to be quite close. The manga counterpart doesn't display as many romance elements, which is highlighted much more in the anime version.
Powers and Abilities
As a member of the twelve guardians, Shimon is a highly capable exorcist and his skill has allowed him to become the youngest heavenly commander.
Enchanted Gear: As an exorcist, Shimon can use Enchanted Gears to fight impurities.
Heavenly Flight Expose Charm (天翔顕符 Tenshōgenpu?): As one of The Twelve Guardians, Shimon bears the title of Crimson Phoenix thus able to wield its Enchanted Gear.
- Shuzen Zappa (朱染雀羽 Shuzen Zappa?): By using his talisman, Shimon changes his sword into a powerful giant red and yellow flaming sword that he uses to exorcise impurities.
- Sekitei Mugen Byobu (赤鶙無限屏風 Sekitei Mugen Byōbu?, lit. "Vermillion Bird Infinite Folding Screen): 
- Goten Karura (降天迦楼羅 Gōten Karura?, lit. "Descending Garuda"): Shimon changes his sword into a flying gear with wings that resemble a sword which is the true form of Shuzen Zappa and attacks his opponent using them.
- Shuzen Zappa Matoi Kajiri (朱染雀羽 纏神呪 Shuzen Zappa Matoi Kajiri?, "Scarlet Plumage Mystic Spell Equip"): With Suzaku Meikyo-fu (朱雀明鏡符 Suzaku Meikyō-fu?, "Suzaku, Clear Mirror-Charm"), Shimon unleashes the power of the Guardian Crimson Phoenix that increases his speed and power by ten folds. He first uses this against Hijirimaru and is able to overpower him.
- Sekitei Mugen Byobu - Aratame (赤鶙無限屏風・改 Sekitei Mugen Byōbu - Aratame?, lit. "Vermillion Bird Infinite Folding Screen - Modified): 
- Sekiso Ho-o Shinku (赤爪鳳凰神駆 Sekisō Hōō Shinku?, lit. "Phoenix's Red Claws Divine Rush"): 
- Konjicho Rengoku Reppa (金翅鳥煉獄烈羽 Konjichō Rengoku Reppa?, lit. "Garuda's Extreme Tempered Feathers"): 
- The name Shimon means "samurai, warrior" (士) (shi) and "gate" (門) (mon).
- Shimon resembles Neku Sakuraba from The World Ends With You:
- Both have similar hairstyles
- Both wear headphones
- Volume 12
- Twin Stars Exorcists Manga; Chapter 21.
- Twin Stars Exorcists Manga; Chapter 46.
- Twin Stars Exorcists Manga; Chapter 24, page 7.
- Twin Stars Exorcists Manga; Chapter 28.
- Twin Stars Exorcists Manga; Chapter 28, page 8.
- Twin Stars Exorcists Manga; Chapter 28, page 9.
- Twin Stars Exorcists Manga; Chapter 28, page 41.
- Twin Stars Exorcists Manga; Chapter 74, page 18-19.