The following contains spoilers for Spy x Family Episode 8, "The Counter-Secret Police Cover Operation," now streaming on Crunchyroll.
When a mind-reading orphan named Anya is adopted by super spy Loid Forger, Loid's mission becomes her life. As an orphan, Anya is terrified that the family she and Loid are building will fall apart if his mission fails, and she will do everything in her power to make sure that doesn't happen.
Adding the brutal assassin Yor to the mix as Loid's wife and Anya's new mother, the family dynamic is so adorable, it's almost deadly. But there's more to this new family than meets the eye, especially when Yor's younger brother Yuri bursts onto the scene. Not only does Yuri arrive at the Forger residence already jealous about his sister's new husband, but he poses a significant threat to Loid's position as a spy.
Who Is Yuri In Spy x Family
Episode 8 of Spy x Family introduced Yor's brother Yuri to the mix. While his relationship with Yor seems strange, there are reasons he feels so close to his older sister. It's Yuri's position as a counterintelligence agent for the State Security Service that puts Loid and Yor both in danger.
Yuri made quite a memorable entrance when he appeared at the Forger home with the intention of meeting his new brother-in-law. In the anime's first few episodes, Yuri had been an enigma of sorts. From what Yor had said, the two siblings had a close relationship after the death of their parents. But it seems Yuri is very close to Yor -- so close that some have suggested he seems to have a bit of a sister complex. He's constantly worried about his sister and when he meets Loid, he immediately doesn't like him. While there are many signs that point to Yuri being a siscon, he isn't like those that are commonly seen in other series.
What Is a Siscon?
A sister complex, or siscon for short, is when someone is extremely attached to their younger or older sister to the point where they are overly protective and/or obsessive. The term has evolved into having more romantic connotations, where the individual is jealous whenever their sister is in a romantic relationship, and they yearn to be their sister's romantic partner instead. However, it is important to note that a sister complex and incest are not synonymous. Most of the time, the sister complex trope is played up for comedic purposes.
In Spy x Family, Yuri does demonstrate some traits of a siscon, such as when he brings her a huge bouquet of roses which is usually more befitting of a romantic relationship. Yuri's logic and common sense go out the window when it comes to Yor. He viewed his two broken ribs as evidence of the overwhelming wealth of love his sister had for him. He even bought Yor's excuse about why she neglected to tell him about her new life. He doesn't like Loid at all, seeing him as a barrier to spending more time with his sister. Yuri is suspicious of him, even fearing that Loid had been preventing Yor from meeting him. For all intents and purposes, Yuri checks off all the boxes of having a sister complex.
Why Spy x Family's Yuri Isn't a Traditional Siscon
And yet, there are aspects of Yuri that set him apart from other siscons. The moments where it looks like he sees his sister in a non-familial light are played up for comedic purposes, like when he panics about Yor using embarrassing pet names to call Loid. In Episode 8, a bit more is revealed about Yuri and his sister's childhood. The two had lost their parents at a young age, and Yor had to become the family's sole caretaker. It opens up an earthshaking revelation: Yor had already started killing when she was just a child. Seeing his sister come home every week covered in blood, only to hand him a book or a snack with her earnings, was painful for Yuri to witness.
This also serves as a possible explanation for why Yuri is so lax when his sister gives him less than plausible excuses. At that age, he must have known his sister was doing an extremely dangerous job; to conceal how concerned he was, the only thing he could do was accept whatever ridiculous excuse she came up with. Yor was working so hard to ensure he was happy and, because he was so young, there was nothing Yuri could do. That's why he works for the Secret Police -- Yor was all Yuri had, and he was going to ensure her happiness and safety.
In Spy x Family Episode 2, when Yor was talking to Yuri on the phone, he was worried that she would end up alone and even offered to introduce someone to her. What's more, to Yuri, it looks like Yor married on the fly (which she did), which is enough cause for him to be worried about her well-being. Yuri is suspicious of Loid not because he sees him as a threat for taking his sister away for any romantic reasons, but because he's afraid of losing her to someone he isn't sure will be able to protect her.