The Summer 2025 Anime Preview Guide - Betrothed to My Sister's Ex

With unmaintained red hair and shabby clothes, Marie, the baron's daughter, has been treated like a servant all her life. Count Granado, the country's richest man, who is said to be a difficult misogynist, falls in love with her at first sight. However, due to a misunderstanding, Count Granado proposes to her sister Anastasia, who looks like a princess, instead of the ragged Marie.

Betrothed to My Sister's Ex is based on the light novel series by author Tobirano and illustrator Mai Murasaki. The anime series is streaming on Crunchyroll on Fridays.

I like that Betrothed to My Sister's Ex is making Kyros so knowable - and likeable! - pretty much straight away. Don't get me wrong, plenty of romances have done well by making their protagonists' surprise fiancés and husbands into mysterious enigmas whose softness has to be coaxed out over time. Kyros has every reason to be aloof and bitter, too. Growing up as the dark-skinned child of a concubine who was just one poisoned cookie away from getting murdered to further his more “traditionally” noble relatives' ambitions, Kyros had to learn early what it means to be forced to participate in a society of prejudiced aristocrats who will shower you with praises to your face until they can spit on your name in private.

Instead of making him into an inscrutable statue of repressed feelings, though, Betrothed to My Sister's Ex takes the very entertaining route of having Kyros be an adorably lovesick little dork. This guy has been infatuated with Marie since the day they met at the birthday party, and he only ever agreed to marry Anastasia because of mixing up the sisters' names. On the one hand, this makes some of the dramatic potential of the show's title feel like a bit of a bait-and-switch, since Kyros never gave a damn about Marie's sister to begin with. He had sworn off love entirely before he met our heroine, and he is still dead-set on winning her heart. The show might as well be called Betrothed to the Genuinely Sweet and Multifaceted Guy Who Has Only Ever Had Eyes for Me and Will Not Stop Until I am the Happiest Woman in the Land.

Then again, there's nothing wrong with one of these romances being unabashedly committed to giving its audience the warm-n-fuzzies, is there? Besides, it's not as if the couple has just magically arrived at their fairy-tale ending by Episode 2. Marie was still so overwhelmed with the changes in her life that she outright rejected Kyros' proposal, so Kyros had to figure out a way to clear up this misunderstanding before he ruined his chances with her for good. So, instead of asking “Will our heroine find love?”, this anime is all about figuring out how Marie will be able to overcome her trauma and meekness now that she has been gifted the sweetest and handsomest simp in the land to be her lifelong partner and ally.

It might not make for the most gripping storytelling, but Betrothed to My Sister's Ex continues to be cute and heartwarming, like a fresh slice of cake that has been shaped into some cute animal face. I'm supposed to be on a diet, so I don't know if this is the kind of sugary indulgence that I need to add to my plate this season, but I can easily see it becoming a mainstay for folks who need to satisfy their anime sweet tooth over the summer.

I need to get my incredibly nitpicky complaint about Betrothed to My Sister's Ex out of the way up top, because it has been driving me crazy. Our main heroine, Marie, has these strands of bright green on the fringes of her otherwise fire-red hair. It makes her look like she's constantly standing in front of a green screen that hasn't been properly keyed out of the shot. It also makes her head look like a ripe tomato. It's an insane element of character design that will haunt me for weeks.

That said, the show itself is fine. Pretty cute, even. It's your typical “Cinderella Story” type of scenario: Marie is the dowdy girl dressed in rags that the rest of her noble family either ignores or abuses. That is, of course, until the day she somehow ends up…well, just look at the title. For anyone who might be curious, this isn't some kind of wacky love-triangle type of romance. Marie only gets the opportunity to leave her crappy home life and find happiness with Count Kyros because the sister everyone liked got killed in a carriage accident in between montages, Disney-style.

Still, I said this cartoon was "cute"—not "violently depressing". As you can imagine, Marie's life really does get better once she gets involved with the Count (who she managed to impress completely by coincidence before either of them knew who the other was). Sure, the guy starts off a bit brusque, but only to the degree that all of the love interests in these anime Cinderellas are required to be. He clocks Marie's family's abusive behavior pretty much immediately, and his servants all instantly take to her with therapeutic baths and fashion makeovers. Kyros' cool, hot mom even shows up and takes a shine to Marie within seconds of meeting her.

Compared to the more natural (and, frankly, interesting) drama of series like My Love Story!!, this one feels like it is trying to speedrun through the usual plot beats to get to the cute stuff. That's totally fine. I don't know if Betrothed to My Sister's Exx is going to be my thing in particular, but I can recognize it as a light and fluffy slice of romance-anime cheesecake. Hopefully Liu Liu or one of the Granado's servants can hook Marie up with some quality hair dye, though.

I called Marie a Cinderella figure last week, but there's one very big difference between the two characters: Cinderella never doubts her own worth. It's everyone else who belittles her; Cinderella herself does what she has to to escape from her terrible situation. (I'm talking about the tale type in general, not the Perrault or Grimm versions specifically; those are the best-known variants.) But Marie lacks that. When Kyros tells her that it was her he wanted all along, he just confused the names, she patently doesn't believe him. Her parents' voices in her head are too loud, their jeers drowning out Kyros' earnestness. He's got his work cut out for him if he wants to break through her combined defensive shell and patent disbelief.

It's a good thing he's got Mio! His flashback shows that Mio's been with him for his entire life, and that's important in a couple of ways. For one, it means that she's got a firm grasp of his personality and how to get through to him, but the more important reason is that she witnessed his childhood. Kyros is, more or less, illegitimate – his mother was his father's concubine, not his wife. Because Lady Laura, the legal wife, only bore daughters, Kyros became the heir, an insult so grave that Laura took her own life rather than watch it come to pass. (Or possibly out of guilt at not having a son for her husband; she doesn't seem to have been a bad person, just an unhappy one.) She saw Kyros' mother treated like a second-class citizen, and the fact that he was the heir upset her. Mio knows what makes him tick and that he and Marie might have a bit more in common than either of them realizes – and she's got the no-nonsense personality to make them both move in the right direction, with or without their knowledge.

She's also in some ways the most aware character in these two episodes. When Mio remarks that she needs to go home after letting Kyros use her for a night's entertainment, he's stunned, but she is enraged. While Kyros doesn't know what to think and Marie sees nothing wrong with her father's expectations, Mio is ready to destroy the entire family, burn their home, and salt the earth. I think that even if Kyros weren't in love with Marie, Mio would be making it her life's mission to help her.

It's not hard to get behind that sentiment. This poor woman has never slept in a comfortable bed, never seen herself with her hair brushed, or eaten good food, despite being the daughter of a baron. She deserves better than she's gotten. Kyros might be wallowing in his mistakes and the impact they've had on his marriage plans, but Mio's going to make damn sure this wedding comes off. Now, if she could just scrub the green from Marie's hair, everything would be perfect.

Strictly speaking, the title of this show is a lie. Not that heroine Marie knows that – as far as she's concerned, she'll always play second fiddle to her older sister Anastasia. Even her birthday celebration was co-opted to become Anastasia's debutante ball, making her feel stupid for having ever thought that the party would be for her. But the one person who sees Marie as desirable and good is Kyros, heir to a dukedom. Shortly after his encounter with her at the party, a passionate letter asking for the daughter of the house's hand in marriage arrives, and whether it was addressed specifically to Anastasia or he thought that Marie was Anastasia is unclear. But it's very clear to everyone except the family that the proposal was always intended for Marie. So she's hardly betrothed to Anastasia's ex; he was always her fiancé.

That doesn't make this any less of a Cinderella story, and if you enjoy those, I think you'll find things to like here – although be warned that it comes with domestic abuse. Not only is Marie forced into ragged, too-short dresses (hers don't touch the floor like all the other women's), her mother and father also physically abuse her, and following Anastasia's demise, they're not shy about screaming that they lost the better daughter. Poor Marie has heard this for most of her life (although a flashback indicates that maybe it wasn't always the case), and the trauma has resulted in her self-esteem being somewhere underground. She firmly believes that she's ugly and unwanted, that her hair is out of control because red hair is repulsive, that she's never going to be good enough. Her father doesn't hit her (as much), but he still keeps gaslighting her and reinforcing that she's not “lovely” or “charming,” and that her intelligence is a detriment in a woman.

While this is nowhere near the levels of awful of Takopi's Original Sin, it can still be hard to take. What saves it is that Kyros is so plainly head over heels for Marie, even if he's surprised by which daughter is Marie. He's taken instantly by her intellect and curiosity, and he wants her to be cared for and happy. If that's not coming through to her right now, it's because she's spent so long living the opposite. This isn't as gorgeous as other recent Cinderella tales, like My Happy Marriage (I hate the green outlines on Marie's hair), and it is treading some well-worn ground. But it also has the potential to be a very enjoyable romance, and I'm looking forward to seeing Marie come into her own with people who love her and wish her the best.

As a counterpoint to the first episode, this episode shows everything from Kyros' point of view—and not just from the time when he met Marie for the first time. The big problem in Kyros' life is that he is the only male son but was born to a concubine and not the Duchess.

The Duchess is a tragic figure. She had only girls and was forced to watch as a lowborn foreign dancer was taken into the house and loved by her husband over her. Despite the pain and rage she felt, she couldn't make herself hate Kyros and tried to befriend the child. However, when Kyros was made the heir over her daughters, she put into place a plan to kill him—to poison the sweets she would regularly give him. Yet, at the last moment, she found she could not go through with it, and instead ate the poison cookies herself. Steeped in unbearable pain and humiliation, she chose to take her own life rather than kill an innocent child. It's clear that Kyros' mother understood what the Duchass had done and why—and so took her son from the Duchy and raised him abroad, far from the Duke and his half-sisters.

The tragedy of the Duchass is a wonderful piece of direction and animation. Much of the story is left unsaid—only through watching character reactions and little background details are you able to piece together the full story of what happened and why. The episode is worth watching for it alone.

Getting back to Kryos' backstory, it's unsurprising that this whole situation drove Kyros away from the idea of love. Moreover, once he became rich and gained the title of count thanks to his own deeds, it was clear that the women he met were only interested in his wealth and position. Of course, all this changed when he met Marie who was more interested in him as a person than the outer trappings that surrounded him.

Going forward, it's clear that the issue lies with Marie. She is fundamentally unable to believe that anyone would ever choose her over her sister—full stop. Even when Kyros tells her exactly what happened with the name mix up and confesses that he loves her, she can't believe it—is literally baffled at why he'd tell such an obvious lie.

It's plain to see we're in for a lot of comical misunderstandings before Kyros is able to make her accept the truth. And normally, I don't know if I'd really be willing to spend my time on that. However, the way the whole Duchess story was handled with such nuance and care makes me want to give this story the benefit of the doubt. I don't know if I'll be watching this one week to week, but I'll definitely marathon it when it's done.

It's interesting the fantasy sub-genres that have been popping up in recent years. Betrothed to My Sister's Ex is the latest in the “abused young woman is sold off by her family and finds happiness being doted on in her new home” sub-genre. It presents a rather laid back kind of story focused on catharsis and healing.

This first episode of Betrothed to My Sister's Ex is a prime example of this. There are clearly antagonists (in this case, Marie's family sans her deceased sister), but the real battle Marie is facing is an internal one. Marie is so psychologically beaten down that she believes she is worthless. Things as simple as a good cup of tea and a bath feels like an undeserved luxury. She doesn't even consider that she was abused until Kyros brings it up directly—and even then she decides that she wasn't. (She was.)

Meanwhile, Kyros is the perfect lead for this type of story. He's not cold or standoffish—which allows him more depth than the standard “cool duke” stereotype common in fantasy romance. Instead, he is embarrassed and enraged by the whole situation. He never wanted to marry Anastasia. He just never even considered that the shunned sister in the garden would be the actual birthday girl—you know, as opposed to the one at the center of said party. It was a simple mix up—and one that almost ended with Marie still trapped in her abusive home.

In the end, whether you'll like this one or not comes down to how much you want to live vicariously with Marie's tale—how much you too wish you could leave your crappy live behind and be pampered by servants who think you're cute, a mother-in-law who supports you, and a husband who wants to bend over backward to give you the life you deserve. This anime is exactly what it's trying to be—well except in one tiny area. What is up with those green highlights?