|“||One who's betrayed in the past will do it again.||”|
–Sonosuke Izayoi, Danganronpa 3: The End of Hope's Peak Academy
He is a member of Future Foundation and the leader of the 9th Division. His responsibility is to aid in the preparation, supply, management and distribution of weapons.
During his time at Hope's Peak Academy's Class 76th, Sonosuke's title was Ultimate Blacksmith (超高校級の「鍛冶屋」chō kōkō kyū no “kajiya” lit. Super High School Level Blacksmith) until he was expelled after getting involved in a bombing incident.
Sonosuke was killed by his romantic partner, Ruruka Ando, who forced him to violate his NG code. He is the second person to violate his NG code in the Final Killing Game, and the sixth to be killed overall.
Sonosuke appears in the 30-minutes long OVA, Super Danganronpa 2.5: Nagito Komaeda and the Destroyer of the World as a part of Nagito Komaeda's imagination world and Danganronpa 3 spinoff manga, Danganronpa Gaiden: Killer Killer.
Sonosuke is a man in his early twenties, around 23 at youngest (about 18 in Danganronpa 3 - Side: Despair).
He has a tall, lean build. He has pale blonde hair, sharp brown eyes, pale skin and a serious expression. He wears a red trench coat, and wears his Future Foundation ID on his left shoulder. Sonosuke wears dark red finger-less gloves, baggy black pants and dark brown boots.
It's also stated there is a multitude of weapons hidden in his coat.
Being the former Ultimate Blacksmith, Sonosuke is skilled at developing and using different weapons, and he stocks all kinds of hidden weapons inside his coat. Though usually meant for practical use, he can also make ones for collection purposes and he will forge basically any blade upon request.
Sonosuke is stated to be a "silent type", who avoids talking to others, the only exception being his romantic partner Ruruka. He is incredibly loyal and very protective of her, drawing a hidden weapon from his coat on any person who gets close to her. Sonosuke loves Ruruka's candy and Ruruka seems to feed him as a reward, him often resting his head on her lap. Though otherwise calm and serious, the way he eats candy and says "dewicious" is rather comical.
To protect Ruruka, Sonosuke doesn't hold back and show his full splendor towards his enemy. Without any remorse, he set a trap that severely injured Seiko's right hand and took out all of his hidden weapons to fight her until she reached her demise.
Once Sonosuke's trust is broken, it is very difficult to gain it back, as he believes "once a traitor, always a traitor". However, he doesn't mind when Ruruka betrays him or even when she takes his life, as he loves her very much and thus doesn't consider it a betrayal.
Even though he is described as "cool" silent character and has a calm voice, in the official English dub he can sound notably angrier and more aggressive, and sometimes he uses language unlikely for the character (for example, "babe").
Skills and Abilities
Sonosuke's parents who apparently also blacksmiths taught him from a very young age. As a result of the endless teaching and experience, Sonosuke became very skilled at forging materials mainly weapons. In the Academy, he has opened his own shop and take requests from people to forge any weapons that requested. He created weapons for two purposes, for practical and collection purposes. He takes a special interest in weapons that would typically used by ninja. When he joined the Future Foundation, Sonosuke is trusted with the distribution of their weapons.
Sonosuke has much fighting experience. He is shown fighting against the Ultimate Despair and Seiko Kimura with his knives.
Sonosuke has exceptional aim, being able to throw his knives where he chooses and rarely misses.
In addition to forging several types of weapons, Sonosuke is shown to be able to create many kinds of traps, such as explosives that can be triggered with a switch or pressure activated traps.
Sonosuke is quite tactful when it comes to battle. He always prepares extra weapons and traps before engaging into a fight.
Prior to the Tragedy
Sonosuke comes from a family of blacksmiths and his parents taught him their art from a young age.
He also has gone to the same school with Ruruka and Seiko all through elementary, middle and high school. He is in a romantic relationship with Ruruka.
As a teen, Sonosuke was scouted to attend Hope's Peak Academy as a part of Class 76th as the Ultimate Blacksmith. Around his second year, he opened his own shop.
During their practical exam in their second year, an incident involving Nagito's plot to stop the exam caused Seiko's drug being mixed up by Ruruka and used her super-laxative instead of a strength drug in Ruruka's pastry, combined with Seiko, unfortunately receiving Nagito's bomb switch (which was later triggered, resulting in an explosion), resulted in Seiko, Ruruka, and Sonosuke expelled from Hope's Peak Academy an estimated 2-3 years before the Tragedy. Sonosuke agreed with Ruruka's point of view and felt betrayed by Seiko, placing the blame of expulsion upon each other and caused a rift in their friendship.
Chapter 10 - Killer Killer Killer
When Shuji Fujigawa attempts to fatally wound Misaki Asano by piercing her in the back, Sonosuke throws a blade and managed to throw Shuji's knife at the last second. Juzo Sakakura, Ruruka, and Ikue Dogami appear alongside him, attempting to fight Shuji, seeing as he has harmed a member of the Future Foundation. To his delight, Ruruka occasionally praising him, as well as giving him orders.
As Sonosuke, Juzo, Ikue cornered the real Killer Killer, he detonates a bomb and makes an unseen escape. Sonosuke reflexly moved to Ruruka's side and disappointed as Shuji managed to escape from their grasp.
At some point in time after getting recruited by Koichi Kizakura for the Future Foundation, he became the head of the 9th Division. His responsibility as the 9th Division leader is to aid in the preparation, supply, management and distribution of weapons.
At the beginning of the episode, Sonosuke along with Kyosuke Munakata and Juzo were protecting some members of Future Foundation from Fuyuhiko Kuzuryu, Peko Pekoyama, Nekomaru Nidai, and Akane Owari's attack.
Sonosuke was present with the other ten Division leaders of Future Foundation to discuss Makoto Naegi's betrayal. Despite being one of the Division leaders, he didn't follow along with the discussion as he was resting his head on Ruruka's laps and eating her sweets, commenting on how tasty it was.
As Makoto, Kyoko Kirigiri, and Aoi Asahina arrived, Juzo immediately handcuffed Makoto, injuring him in the process. When Hina tried to intervene, Sonosuke and Ruruka threatened Hina, Sonosuke throwing his kunai at her. The trial was postponed and Sonosuke stayed at the boardroom until the Future Foundation's off-shore facility got attacked.
Kyosuke gathered everyone inside the boardroom as the attack was getting harsher. Everyone started to panic as Daisaku Bandai confirmed that all the exits to the building has been cut off. Later, a sleeping gas was thrown inside the boardroom and Sonosuke reflexively protected Ruruka, but eventually all of them were rendered to sleep.
After he woke up, Sonosuke and the others found a Monokuma bracelet had been set up on their wrists. He learned that Monokuma has been resurrected and announced the Final Killing Game of mankind's last hope Future Foundation via the monitor, started with Chisa Yukizome's body, which fell from the ceiling.
Sonosuke keep sticking together with Ruruka when Monokuma announced the rules of the Final Killing Game. He refused Ruruka’s reward judging from the dire situation that they faced. Later, he and Ruruka point at Seiko, believing she is the traitor, however Kyosuke believes they are pointing at Makoto because Seiko was hiding behind Juzo.
Following Makoto’s escape, Ruruka and Sonosuke parting from everyone to hide from the traitor. Sonosuke agreed with Ruruka that the traitor has to be Seiko, stating that someone who have ever betrayed someone in the past will do it again in the future.
Sonosuke and Ruruka were in the entrance together and promised to not betray each other's trusts. Later, they encountered their former classmates, Seiko who accused them being the traitor. As Ruruka and Seiko's argument heated, Seiko ate some sort of green pill that she invented, causing her to go into a beserker-like state. Sonosuke threw a kunai at Seiko and held Ruruka on his shoulder, started to run from Seiko.
Sonosuke and Ruruka set many traps on the wall to halt Seiko's pursue. Unfortunately, due to Seiko pills' effect, she was immune to Sonosuke bombs' damage. Later, Sonosuke tried to stop Seiko alone and letting Ruruka escape, using barrels to barricade the door.
Ruruka tried to calm her former classmate but her words can't get through Seiko due to her hatred for both Sonosuke and Ruruka. It was revealed that due to an event occurred during their time in Hope's Peak Academy, the three of them expelled from the Academy. Seeing further resistance can't hold Seiko anymore, Sonosuke once again brought Ruruka to run.
Sonosuke set his doppelganger formed with sharp objects which effectively injured Seiko's right hand. He appeared and dropped various knives to the floor, stating that he will kill her in the name of love and delicious sweets of Ruruka.
Sonosuke proceeded to battle Seiko in a short time before she drew her attention to Ruruka. He moved to Ruruka's side inside the arena's monitoring room. After Ruruka learned Seiko's NG Code, Sonosuke listened to her whisper and soon left the area to prepare his weapons to finish Seiko.
Inside the lounge, Sonosuke was ashamed to choose a gun over a blade. Suddenly, the ground shook and revealed a secret entrance behind a book shelf, distracting Sonosuke.
After the time limit hit, Sonosuke was found dead, along with Seiko, by Kyoko, Ryota Mitarai, and Koichi with the attacker's signature knife stabbed into his chest. While Kyoko inspected his body, she found a white powder-like substance on his face, with blood directly under his left eye.
Based on her analysis of Sonosuke's corpse, Kyoko accused Ruruka as the culprit instead of the unknown attacker. She explained that he had been poisoned by his bracelet, which displayed the NG code of putting food in his mouth, and the attacker's knife had come from Seiko's body to disguise the true cause of death. Kyoko theorized that Ruruka had killed Sonosuke by force-feeding him one of her sweets; given the presence of the secret entrance in the lounge. Kyoko suspected the motive Ruruka had to kill her romantic partner was because of her forbidden action which was allowing anyone to leave the building.
Ruruka thought back to the events that lead up to Sonosuke's death. Sonosuke told Ruruka about the secret exit, sealed it up, and laid down several traps to prevent someone from getting out. Ruruka asked Sonosuke not to betray her again, and Sonosuke said he wouldn't. Ruruka kissed Sonosuke, and then slipped a sweet into his mouth. Ruruka cried as she told Sonosuke she can't risk him betraying her, so she'll betray him first. Sonosuke said it wasn't a betrayal and that he understood. He then kissed Ruruka again and confessed his love to Ruruka before he finally took his last breath.
Sonosuke appears in the OVA as a part of Nagito's imagination world.
Both Sonosuke and Ruruka were apart of Class 76th. They are a romantic couple and close since childhood, which is confirmed by their school profiles. Sonosuke is the type of person who doesn't like to speak or interact with others, with Ruruka being the exception. According to the relationship chart, they have a mutual trust and reliance on each other. He says that he cares about Ruruka more than he cares about himself.
Sonosuke is shown to be intimate with Ruruka, such as laying his head on her lap, but seems to be seeking Ruruka's candy as a reward, as he happily allows her to drop sweets into his mouth. The two seem to be partners, Sonosuke protecting Ruruka, and receiving her treats as a reward.
After Ruruka told Sonosuke not to betray her, he swore he wouldn't "by love and delicious sweets". However, when Sonosuke discovers a secret exit, Ruruka appears to be so afraid of a possible betrayal that she kills him by breaking his NG code, betraying him before he can betray her. However, Sonosuke doesn't consider it a betrayal and says that he loves her, giving her a one final kiss right before he dies.
It's been described that at least some of Ruruka's candy are as strong as narcotics and give her an ability to control other people. However, while Sonosuke really loves her candy, it seems he is not addicted to them in this manner as he continues to protect and truly loves her while not allowed to eat any candy during the Final Killing Game.
Seiko was an acquaintance of Sonosuke's and fellow member of Class 76th. The two were on good terms, as both were close friends of Ruruka since childhood. However, the three unintentionally got involved in a school bombing thanks to Nagito and were expelled because of this. Sonosuke believes Seiko to be responsible for the incident and now distrusts her, and is determined to protect Ruruka from her.
A drawing from Lerche's twitter shows Ruruka reconciling with Seiko in the afterlife, therefore giving Sonosuke no more reason to despise her. However, Sonosuke is seen threatening Seiko with his knife, telling her to eat Ruruka's treats as they are dead anyway. It's possible that Sonosuke and Seiko are simply acquainted with each other again, just as they were initially.