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Shin's older brother. He admired Shourei and looked up to him as a hero, seeing him as someone who knew everything and could do anything. Shourei devoted himself to protecting Shin after they were taken to the internment camps.
When the siblings recieved news of their mother's death, and Rei recieved his enlistment directive, Rei ended up directing his anger regarding the situation at Shin, blaming him for their mother's death. Rei chokes Shin and nearly kills him, but is pulled away by the priest who was caring for them just in time. The priest doesn't allow the two to meet after that, and Rei departs for the battlefield soon after without ever exchanging another word with him. Shin is left to believe that his brother blames him and wants him dead.
Soon after his own enlistment, Shin discovers the remains of his brother's juggernaut and adopts his brother's personal mark as his own. He begins to hear his brother's voice among the voices of the legion, and understanding what happened, devotes himself to finding his brother and laying him to rest.
Shin does eventually find his brother in the form of a Dinosauria on the battlefield and confronts him, finally coming to terms with his brother's misplaced anger and accepting that it wasn't his fault that his brother strangled him that day, nor was he responsible for his parents' deaths. He defeats the Dinosauria. In his brother's final moments, Rei finally apologizes to Shin, shocking him. And for the first time since the day Rei choked him, Shin is able to cry.
Shin's paternal grandfather and the current head of the Nouzen Clan. Although they never met before the war, Seiei was aware of Shin and his brother. He secretly sent them a picture book which contained the exploits of their ancestors, as a birthday gift. After the war began, however, all communication between the Empire and the Republic was lost. Thus, no information about Shin and his family reached Seiei for several years.
When Shin and his fellow processors were rescued by the Federacy, Seiei had requested a meeting with his grandson repeatedly. Shin, however, still suffered from emotional damages incurred during his time in the Eighty-Six Sector and did not consent to meet his grandfather.
Seiei finally met his grandson for the first time after he came back from the United Kingdom, much to his joy. Although Shin's had yet to feel any emotions toward his grandfather, they both agreed to try forging a familial bond between them. During his vacation in The Alliance of Wald, Shin bought picture postcards as a souvenir for Seiei.
Shin's maternal grandmother.
- Before Meeting
Shin was always Lena's primary contact point for the Spearhead Squadron, as such the two would talk frequently over Para-RAID discussing both business and other topics. Shin was cold, curt and honest to a fault with the Handler; he thought of her as annoying and naïve. His opinion of her would change from her persistence in her cause, as well as from their time bonding over their shared link to Shourei. He would grow to respect her input and to be thankful of the things she had done for them, even something as practically insignificant as sending them fireworks. Shin would ask her to not forget him and the Spearhead Squadron during the Revolution Festival. In his final letter, he asked her to leave them flowers at their final destination.
His time spent talking to Lena left an impact on him, though he couldn't exactly understand his feelings towards her. When asked about the chance of Lena's survival, he deflected, to which Raiden noted he wasn't being honest with himself. 
Shin felt a burden was lifted from his chest once he managed to tell Lena that he was going ahead of her, as if he was finally free of his duty as the reaper of the Eighty-Six by entrusting their memories to Lena. This was the reason why he was devastated to learn that the Republic had fallen at the hands of the Morpho, and at the possibility of Lena's demise. Once again, instead of Shin entrusting himself to another, it would be himself that was forced to remember a fallen comrade.
Shin was surprised that the Republic had survived, even more so that an Alba officer was commanding on the frontlines carried by a one of her Processor's Juggernauts. As he did not know she was Lena at that moment, he thought of the things she had said—that she would continue to fight for her country and comrades—as awfully rich coming from the cowardly Alba. He interrogated her, asking for what purpose did she fight; only then did she reveal her name and her mission to reach the Spearhead Squadron's final destination.
Shin was relieved to learn of her survival. He did not reveal himself to be Shin, as he didn't want their reunion to be on the battlefield, especially after the effort Lena put into reaching their final destination. Shin figured she deserved better than to leave her mission incomplete by introducing himself.
Their second reunion at the Processor memorial was less confrontational. They regarded each other with a salute before Shin revealed their identities. He was still curt, but he wore a smile when speaking to her. It was through Lena that Shin was able to begin climbing out of his suicidal despair.
- After Meeting
Once Lena joined the Eighty-Sixth Strike Package, the two had to reset their relationship. They decided on a superior-subordinate relationship while on duty, and a friendship without the need of ranks in private. For the first time, they consistently referred to each other as Lena and Shin rather than Major Milizé and Captain Nouzen. Their relationship wasn't all fine during the start. Shin considered Lena to be shackled by the sins of the Republic which she did not commit; while Lena considered Shin to still be trapped in the Eighty-Sixth Sector, unable to search for a future beyond fighting the Legion. This lead into frequent awkwardness as one tried to confront the other.
Shin's affection for Lena is obvious to everyone, except to Shin and Lena. Frederica makes note of it after their reunion. Theo calls the two "a troublesome pair", referring to the need to cover for the two by holding back Frederica and Kurena so they can spend time alone. Vika also seems to notice it rather quickly, expressing his fear of Shin killing him for getting Lena to wear the Cicada, to which Lerche responds by surprisingly noting that the reaper must be enamored with Lena.
Shin wants to show Lena the sea, and he holds onto this as the only future he can wish for and his reason for fighting. Although he first settles on this wish in Under Pressure, it isn't until Darkest Before the Dawn that he is able to admit his wish to Lena, in a moment where he begs her not to leave him behind.
Shin is shown to be particularly protective of Lena, and gets especially scared when she's at risk. Contrary to his other comrades, whom he accepts may leave him behind some day, Shin admits that he doesn't even want to consider the possibility of losing Lena. In the rare moments when Lena suggests that Shin should leave her behind if it would save him, Shin becomes immediately defiant. These are the only instances when Shin refuses a direct order from Lena.
During their R&R in the Alliance of Wald, Shin finally came to terms with his feelings for Lena. He spent most of the trip trying to find a good time to confess, and eventually was able to after the fireworks display at the ball. Lena responded to his confession by kissing him, but ended up so flustered that she ran off before giving Shin a verbal answer, leaving him very confused.
Aboard the Stella Maris during their mission in the Regicide Fleet Countries, Shin tries to push for an answer from her after finding her wearing the Cicada. Lena deflects, avoiding a proper answer. Shin catches her off guard by kissing her, calling it payback for her catching him off guard back at the party, and telling her to let him know whenever she's ready with her answer.
Shin saw Frederica as nearly a mirror of his past self, the headless knight which chased after his brother Rei. He sympathized in her mission to relieve Kiriya and developed a pseudo-sibling relationship with her. They argue and quarrel, but at the end of the day, Shin would protect Frederica when push comes to shove.
Raiden is Shin's closest friend and right-hand man. In the beginning, Their relation was rather tempestuous; Raiden, who had lost almost all his friends within a mere first six months, found Shin's suicidal tendencies and emotional detachment irritating. After serving together for another half a year, Raiden finally lost his patience and got in a fist-fight with Shin. Raiden lost that fight badly, describing it as one-sided. Raiden eventually learned the cause of Shin's behavior and became better at reading his thoughts. Their relation was gradually improved and became friends later.
As Shin had spent a long time with Anju, she's considered family to him. He gave Dustin approval to pursue a relationship with Anju and supported them, as he wished for her to move on from Daiya's death and find her own happiness.
Kurena admires Shin for bearing the burden of carrying the names and memories of his dead comrades with him. After witnessing Shin euthanizing one of their mortally wounded squadron mates after a battle, she resolves to help him carry his burden. In order to do so, she sharpens her shooting skills to be able to perform the same duties as Shin. However, she eventually realizes that she is not capable of being the same as him.
Kurena's admiration for Shin has developed into affection, a topic her squadron often uses to tease her. The feelings are not mutual, since Shin has grown to view her as a little sister. Despite this, she was persistent in trying to help him and gain his attention.
One of few Republic citizens who volunteer for the Eighty-Sixth Strike Package. Shin was not particularly close to him at first. But after becoming aware of Dustin's affection towards Anju, Shin implicitly gave his permission for Dustin to pursuit a relationship with her by threatening to feed him to the Legion if he ever make Anju cry.
The relationship between Shin and Shiden resembles that of cats and dogs. Although they do not really hate each other. there is still a sense of rivalry between two captains. Their rivalry is mostly one sided on Shiden's part. It's implied that their rivalry mostly stems from their shared affection for Lena.
Shin's childhood friend.
Bernholdt is Shin's assistant. The senior Sergeant holds a great deal of respect for Shin, despite being many times his age. He wishes for Shin and the rest of the Eighty-Six to find a future and never lose their humanity, unlike the Vargus who can't see themselves as anything but wolves.
Shin's commanding officer both when he was in the Nordlicht Squadron and the Strike Package. At first, Grethe had difficulties to connect with Shin. Although she genuinely tried to help him, Shin's suicidal tendencies and emotional detachment seemly rendered her effort futile. Their relation was improved after the elimination of the Morpho where Grethe started teasing Shin's relationship with Lena.
Federal Republic of Giad
Shin's first friend after becoming a Federacy citizen. Being a kind, sociable young man, Eugene quickly developed friendship with Shin after their first meeting. Both Shin and Eugene enrolled to special officer academy together. Though they joined different units, Shin would later met Eugene again after he was dispatch to reinforce the 141st Regiment. They had a pleasant conversation before it was interrupted by the Legion's attack. Unfortunately, Eugene was mortally wounded in the subsequent engagement by Legion's artillery fire and Shin personally euthanized Eugene at his final request. Afterwards, Shin would visit Eugene's grave occasionally.
- Volume 1 Interlude 3
- Volume 1 Interlude 4
- Volume 1 Interlude 1
- Volume 1 Chapter 7
- Episode 2
- Volume 1 Chapter 2
- Volume 1 Chapter 5
- Volume 1 Epilogue 1
- Volume 2 Chapter 4
- Volume 3 Chapter 8
- Volume 3 Chapter 9
- Volume 3 Epilogue
- Volume 1 Epilogue 2
- Volume 4 Chapter 1
- Volume 5 Chapter 2
- Volume 5 Chapter 3
- Volume 6 Chapter 3
- Volume 7 Afterword
- Volume 8 Chapter 3
- Volume 7 Chapter 4
- Volume 6 Chapter 1