The story of OniAi focuses on the life of two twins, Akito and Akiko Himenokōji (voiced by Ryōta Ōsaka and Ibuki Kido, respectively), living together and their budding relationship. The series starts off six years after an incident with the twins losing their parents in a car accident, which resulted in the two being separated and not having seen each other in that time. Akito is now transferring to Saint Liliana High School, coincidentally the same school his sister attends, which upon his arrival, the ecstatic Akiko moves into his dormitory. Unbeknownst to Akito, we learn that Akiko has a very serious brother complex...

The main story line of OniAi (as thin of plot as it is) is Akiko essentially attempting to hook up with her brother, which usually ends in comedic failure. One of my favorite examples of this is when she is taking a bath, she tells him he can take a look and she just keeps waiting and waiting for him to sneak a peak of her, setting it up as to where it would be easy to accomplish this, yet when he doesn't, she flips her lid. Scenes like these in the show can be funny but at the same time pretty uncomfortable to watch due to these characters being related.

Thankfully for Akito, he and his sister are not alone for too long as they are joined by several other women vying for Akito's attention by the end of the first episode. First we have Anastasia Nasuhara (voiced by Minori Chihara), a second year student whom is from Russian heritage and has a bit of a cold personality, she is consistently at odds with Akiko over Akito. Next is Ginbei Haruomi Sawatari (voiced by Asami Shimoda.) Ginbei is the tomboy of the group and Akito's childhood friend whom also has a crush on him, despite Akito treating and seeing her as a boy and his best friend, much to her frustration. Lastly we have Arashi (voiced by Eri Kitamura.) Unlike the other two women I mentioned, Arashi is very open and aggressive about her sexual advances, because of this (and the fact she openly admits to having over 30 lovers) she is referred to as "The Predator." The presence of these women, usually puts Akiko's advances to a minimum.

After the 5 of them are living together for a while, we're introduced to one last character to shake up the dynamics of the series, her name is Arisa Takanomiya (voice of Sumire Morohoshi.) Arisa shows up about halfway into the show, hired by Arashi to be the housekeeper. Despite only being 12 years old, besides being a genius, it turns out Arisa is actually Akito's fiancee and has returned hoping to get him back.

The majority of OniAi is episodic or primarily focuses on fan service, for example one episode is about the women taking Akito with them to shop for swimsuits. Another is Te characters find a stray cat, and they try to decide who would be the best suited to take care of it. While the majority of the series is like this, there are some exceptions, a couple of my favorite episodes of the series focuses on how Akito actually makes a living to support himself and the other women. He's an erotic book writer, who writes about a boy and his incestuous relationship with his sister, which draws the attention of his editor, Kaoruko (voiced Megumi Takamoto), whom now thinks Akito has a sister complex (in actuality it's the total opposite) and sets out to try and end it.

Despite a lackluster, weird and disgusting "plot", I actually found myself to enjoy some points of OniAi. It's characters are what really carried the show, and besides the unbearable incest plot it was an OK harem anime that had it's fair share of good moments and solid comedy.

Positives:

- Some genuine laugh out loud moments.

- A solid cast of lead characters.

- Some good story twists.

Negatives:

- Not much of a plot.

Video and Audio
OniAi looks fantastic on Blu-ray. The colors are bold, vivid and strong throughout the series. The characters are well animated with great detail making each character stand out. Attention to detail was especially focused on the fan service scene which I'm not surprised about considering what type of show OniAi is. The only problems one will really find with the animation quality is the far away shots are pretty bad, inconsistent in facial details. Background shots can also be a bit stoic at times since the series doesn't have much to work with in terms of location.

For Audio, unlike every other FUNimation release, the only audio available for OniAi is a Japanese TrueHD 5.1 language track. The entire Japanese cast does a fine job bringing their characters to life. The Audio and Dialogue is crisp and clear throughout the series, with no noticeable dropouts or distortions in the quality.

Extras:

- 6 shorts that are approximately 3 minutes apiece. They are just fan service gags that add little side stories to the plot.

- Textless opening and closing themes.

- Standard FUNi trailers.

Overall:
OniAi is a disgusting show, plain and simple, its a series about a sister in love with her brother, this show is most definitely in acquired taste. The only reason I'm awarding this show 2 stars is because it has a solid supporting cast and some funny moments. There is almost no substance to it. Make no mistake, OniAi is for one specific demographic, because of that, the ridiculous incest plot and it being a sub only release, for the general anime fan I have to say Skip It. There are MUCH better ways to spend your time than watching shows like this. Stop wasting your time on these weird shows and go watch Cowboy Bebop.