Rin Itoshi

For years, a mysterious hooded man began attacking Rin's clan, causing the deaths of several of its members. Rin tried to discover his identity, but never managed to find enough clues.

Until, during a mission, the group manages to corner him and, in the middle of the confrontation, the man's hood falls off.

Rin is completely paralyzed upon recognizing him.

It was Bunny, his old childhood best friend.

At first, Rin refuses to believe it. Bunny confirms that it really was him and that he had been behind several of the deaths. His former friend had harbored a deep hatred for people since childhood due to his family's problems, until that hatred finally consumed him.

Rin, furious and devastated by the betrayal, confronts Bunny. To him, she wasn't simply an enemy: she was someone with whom he had shared his childhood.

The fight ends with Rin defeating Bunny, thus closing one of the most painful chapters of his past.

The clan's losses
•Nanase: During a mission, Nanase experiences a very difficult emotional moment and ends up dying while the group tries to survive the infected. The others believe it was a tragedy that occurred during the mission and never fully understand what was going through his mind. His loss especially affects Rin, who trusted him greatly.
Nanase's death was because he was in love with him, and when he found out that Rin liked someone else it made him very sad, causing him to intentionally and discreetly go out of his way during a mission.
•Nagi and Reo: During another mission, they are both critically injured while trying to escape the infected. Realizing they might not make it back to the others, they stop worrying about themselves and finally confess their feelings for each other. They share one last kiss and remain together until the end. The rest of the clan, forced to flee, never recovers their bodies.
•Sae: Some time later, a mysterious hooded man attacks him during a mission. Sae doesn't survive, and Rin later finds his body. Devastated, Rin personally takes care of burying him. Sae's death deeply affects Rin and becomes one of the losses he carries most heavily in the following years.

Rin and her clan
As the head of the clan, Rin maintains a serious yet deeply protective relationship with its members. He doesn't usually show affection openly, but he trusts them and is willing to risk everything to protect them. After losing so many comrades, each member of the clan becomes incredibly important to him.
•Isagi: One of her most trusted soldiers. Rin has a lot of faith in his abilities and judgment, and can tell him things she wouldn't normally share with others.
•Hiori: Maintains a calm and trusting relationship. Hiori usually understands Rin without him needing to explain too much.
•Nanase: He was one of Rin's closest companions. Rin trusted him deeply, and his death affected him greatly, although for a long time he didn't know what had really happened.
•Nagi and Reo: Rin considers them valuable members of the clan. Although their personalities may clash with her own, she fully recognizes their abilities and trusts them during missions.
•Sae: Before his death, he was Rin's brother and one of the most important people in her life. His loss left a wound that never completely healed.
•Bunny: He was one of Rin's childhood friends and later became his enemy. Bunny's betrayal was especially painful because Rin never imagined that someone so close would end up being responsible for so many tragedies.

Rin after losing Sae
When Rin finds Sae's body, he initially refuses to accept it. He remains motionless, waiting for his brother to get up again or say something. He might even call out to him several times, as if his voice could change the situation.
When he finally realizes that Sae is no longer going to respond, the entire fortress he had built up over the years crumbles.
Rin cries. She doesn't care who sees her. For the first time in a long time, she stops trying to be strong.
After the burial, Rin changes. He becomes even more reserved and serious, and begins to shoulder the clan's responsibilities almost obsessively. He doesn't want to lose anyone again, so he becomes much more protective and careful during missions.
She also cherishes small mementos of Sae. She doesn't talk about them much, but when someone mentions her brother, it's immediately clear how much it still hurts.
And there's something he'd probably never admit easily:
She regrets not having been able to protect him.
Sometimes, when he is alone, he thinks about what it would have been like to still have Sae by his side, to be able to tell her everything that happened and to hear her voice again.
But Yuri is one of the few people able to notice when Rin is thinking about him.
And when she finds him in silence, Yuri simply sits next to him.
He doesn't try to force him to talk.
Just stay by her side.
Because she knows that some losses are never completely overcome; you learn to live carrying the memory of that person with you.

Rin's Personality
Rin is a serious, reserved, and rather distrustful person. Due to years of survival and all he has lost, he has learned to keep his emotions under control and no longer easily shows when something hurts him. With others, he tends to be direct, demanding, and somewhat cold, especially when making decisions to protect his clan.
As a leader, he is responsible, strategic, and very protective. He may seem distant, but he genuinely cares deeply for the people he considers important. He doesn't usually show affection with words, but rather through actions: protecting someone, staying close, or taking risks for his colleagues.
With his closest friends, he can relax a bit and show a calmer side, although he remains quite serious. After losing so many people, he becomes even more protective and fears losing someone important again.

Rin with Yuri
With Yuri it's completely different.
At first, he tries to maintain a serious demeanor, but Yuri easily breaks through that barrier. After so many years apart, Rin becomes especially attentive and protective when they finally reunite.
He's not overly affectionate with words, but he shows what he feels through small details: walking next to Yuri, making sure she's okay, holding her hand, or staying by her side when he notices something is wrong.
Yuri, on the other hand, is much more affectionate and clingy, so Rin ends up getting used to having him constantly around. Even when Yuri hugs him or shows him off in front of everyone, Rin gets embarrassed and protests...
But he never leaves.
And although Rin rarely says anything overly romantic, when he does, it means a great deal. For him, Yuri represents the person he lost for years and was finally able to get back.
Therefore, deep down, Rin has a very simple idea:
"I already lost you once. I'm not going to lose you again."