Oreimo, or My Little Sister Can’t Be This Cute, is a about a very complicated relationship between a brother, Kyousuke, and his sister Kirino. The two sibling’s barley speak to each other, with the younger sister constantly looking down on her older brother. One day Kyousuke discovers his sister’s deep dark secret; she was an otaku with a love of eroge games. He, showing concern for his sister and finally having a peek into her life, becomes involved in her life helping her make new friends and giving her advice. The relationship that was once filled with nothing but antagonism begins to merge into something new.

The story of Oreimo is similar to OniAi in a couple of ways. Both involve brocon, Oreimo also has a siscon. Kyousuke also has a harem of sorts, several girls in Kirino’s orbit who become mutual friends of the siblings are in love with Kyousuke. The story leaves that typical harem comedy feel behind for something a little more serious as you realize where the story is going in the end. We suggest you track down the OVAs if you haven’t seen them for the canonical ending that didn’t air. You also might want to check out Kuroneko (Manga) which has a very different ending for the two siblings.

Shougo Mikadono is the son of a recently deceased industrialist. His father’s will states that in order for him to take over the company and gain his inheritance he has to attend a specific prep-school and get engaged. The school is filled with a number of nice young ladies for him to choose from. And for many of us finding a wife, any wife, in order to become a billionaire industrialist wouldn’t be too much of an inconvenience. Shougo’s only problem is on the day of his father’s funeral a young girl, who he never got a good look at as she spoke from behind a window, declares that she is his long-lost sister. She also reveals to him, via cell phone, that she attends the same school as he does and her goal is to marry him. The mystery of who in his growing harem is his sister almost drives him over the edge. He nearly forsakes all women and loses his inheritance because he’s afraid of committing that great taboo.

The similarities between My Sister is Among Them and OniAi are obvious on a lot of levels. Shougo and Akito both have younger sisters who don’t seem to concerned about incest. The motivations might be different for the girls, but they both seem to want to royally screw their brothers. The stories are also similar in their harem concept. You get a wide cast of girls all interested in the same protagonist and are willing to do a lot of less than ladylike things to make him theirs. You get a lot of comedy in both of these series with classic and still funny, if predictable, falls, gropes and other “lucky pervert” moments.

Keita is a normal high school boy in a blended family. He has two stepsisters, Ako and Riko, who are a year older than him, and a father and stepmother with some rather unconventional views on relationships. Keita has always been doted on by his stepsisters, but as he enters high school the doting twists into something more unconventional for stepsiblings: lust. The comedy isn’t really considered harem, since the relationships seem to only extend to the sisters competing for the brother’s affections. The main exception is with one of his teachers -- a rather young and attractive teacher who hears whispers of what might be going on between the siblings and makes it her cause to intervene. She feels that an older woman can set straight this young man who is being led astray.

OniAi and Kiss x Sis have several similarities and a few major differences. The first of the main similarities are that both have a school component. You see several scenes of cute girls in school uniforms. The second is fan service, OniAi has a lot of fan service and most of it pretty innocent, Kiss x Sis has a lot more fan service and it borders on hentai anime. The biggest similarity is the siscon. Whereas Akito flatly refuses all of his sister’s advances, Keita, perhaps justifying that they aren’t blood relations, gives in on occasion. Kiss x Sis is still a comedy and has a lot of funny moments, some of them just from the shocking nature of the content. If you can get past the taboo topic and some of the lewder scenes Kiss x Sis is a great anime if you like OniAi.

Eita Kidu is a hardworking high school student whose goal is becoming a doctor. He is a student so focused on studying, that he has decided to forgo relationships all so he can earn a scholarship to medical school. So, it’s a shock for most when the beautiful transfer student, Masuzu, decides to publicly confess to him. He is able to see through her confession for what it really is: a lie. Masuzu isn’t interested in love and she recognizes that Eita isn’t interested in love either; she just wants him to be her boyfriend to keep other boys from asking her out on an almost daily basis. He refuses, and she blackmails him into dating her. Everyone, especially his childhood friend and next door neighbor Chiwa, is completely in love with him.

The main similarities in plot follow from this being a harem anime. Eita has to navigate his way through several overlapping relationships with multiple girls as he tries desperately to stay focused on studying for med school. Chiwa is a bit like Akiko, we stress a bit, she has always envisioned herself as Eita’s wife and currently holds the position of best friend. We get a bevy of beauties of various shapes, sizes and development willing to go the extra mile for the future doctor. We recommend watching not for our protagonist but for Chiwa and Masuzu. Chiwa is a spunky girl who sincerely loves her best friend. She is also willing to stand up for herself in the relationship battle, and even gets the parting shot in the last bit of dialogue. Masuzu is a complex character; we aren’t sure about her true emotions or her motives, and it feels like it’s going to take an ice breaker to get through that think cold exterior of hers. She is simply intriguing.

We once again enter a blended family, one where the daughter and mother had not known kindness from men leaving the daughter very suspicious of her new stepbrother. Mitsuki is in many ways a typical teenage girl, especially in the way she shows her resentment by being curt, “not hungry,” and ignoring those she doesn’t like. Her stepbrother Yuuya tries to understand her and is really confused by her treatment of him; at times it’s like she is two different people. In many ways, Yuuya is right about her split personality. Mitsuki is being haunted by Hiyori, a teenage ghost girl, that is in love with Yuuya and is convinced that if she can only have her love acknowledged by Yuuya she can move on. Her means of interacting with and putting the moves on Yuuya is to possess Mitsuki and use her body, leaving Yuuya very confused.

The similarities to OniAi are clear. The story is about the relationship between a brother and sister. Yes, they are stepsiblings and didn’t meet until their middle teens, but they are still brother and sister. The story is also a comedy; anytime you mix a pervy ghost into the mix you are going to have comedic gold. The story is silly and funny and you don’t have to worry about it getting too serious. We mean a ghost, floating around in her nightgown, possessing the younger sister of a protagonist to get into his pants definitely doesn’t leave much room for serious plot or dialogue.

The tale of Yosuga no Sora is one of tragedy. Haruka, brother, and Sora, sister, are twins who move to their deceased grandfather’s house after their parents die in a tragic car accident. The two are accepted in the community and even make friends. Haruka makes friends much faster than his somewhat fragile and distant sister, who refuses to go to school. Sora, like other girls on this list, is in love with her brother, her twin. Her moodiness and jealous behavior threatens to destroy the peaceful existence they’ve found. The difference in this show is it’s not a comedy. Haruka and Sora hide the secret that they are indeed lovers. Even though Haruka knows it is wrong and attempts to break it off, his sister and her emotional blackmail keep drawing him in. You also get one or two side stories dealing with the complex personal relationships of three of their friends. We do see the basic similarities between this and OniAi and Yosuga no Sora, they both deal with bro and siscon. We also will admit that this is a very different take. It lacks comedy, and the serious overtones may not be a good fit for a lot of viewers.