Setsuna's only desire is for his sister to live a happy life. Weak, frail, and constantly bullied, Setsuna believes he's nothing but a burden to his sister and decides to take his own life. As he prepares to jump off a bridge, a mysterious man appears and presents him with an unusual offer. He offers to purchase Setsuna's life in one year after which Setsuna will die in a manner the man chooses. In exchange, he will give Setsuna's sister 10 million yen at the completion of the contract. Skeptical at first, Setsuna accepts. The next morning, thinking It Was All Just A Dream, Setsuna awakens to find two beautiful women sitting beside him. They are Kanna and Rena, Oni princesses who have come to protect Setsuna. The middleman just happened to forget to tell him what the catch is; one of them gets to eat his heart in one year.
The official site (in Japanese) is found HERE. It also has sample artwork.
Onihime VS has examples of:
- Asshole Victim: The serial rapist that Hina kills to convince that Arima that she is an Oni.
- Attempted Rape:
- Arima forces herself onto Setsuna in the first chapter. Before that (on the first page), Arima and her cohorts stripped Setsuna outdoors so that Arima could check out his "equipment". Setsuna has such horrible self-esteem that this isn't enough to make him hate her.
- In chapter 15, as a result of the group date her friends dragged her into, Arima gets paired off with a creepy molester who drugs her drink. Fortunately, Setsuna interrupts while cleaning the hallway outside, distracting the guy long enough for Arima to recover somewhat and drunkenly kick the everloving crap out of him.
- Then there's a Curb Stomped Rena in Chapter 20...
- Aw, Look! They Really Do Love Each Other: Arima and Hina may bitch about how they're stuck together, but they ultimately do care very much for each other.
- Big Damn Heroes: Chapter 15. Setsuna is probably the most low-key example of this ever when he distracts Arima's would-be rapist long enough for Arima to drunkenly beat him down herself.
- Breaking the Fourth Wall: The narration has its moments.
- But Not Too Foreign: Erionelle is Romanian, but of Japanese descent.
- Cut Short: Like Unbalance × Unbalance before it, Onihime VS suffered from this as well with no true ending, much to the fans' utter disappointment. Word of God does have an overpacked schedule, after all.
- Deal with the Devil: Setsuna agrees to drink a potion and die in a year and in exchange his sister's financial problems solved.
- Easy Amnesia: After Kanna drinks a love potion not designed for use on females, she suffers amnesia as a side effect, even forgetting that she's an oni. Additionally, her personality becomes sweet and gentle, the exact opposite of her usual self.
- Hoist by Her Own Petard: Hina, who ends up falling into the trap she set up for Kanna and Rena.
- It Amused Me: It is revealed that the Demon Princesses accepted the Heart Challenge so they could have fun in the human world.
- Kids Are Cruel: When Kana loses her memories she gets picked on by three young boys who dub her titty alien or monster. Setsuns tries to help her with less than stellar results. It takes Arima showing up to drive them off.
- Major Injury Underreaction: Arima doesn't seem that fazed after getting blasted in the chest with a lazer in Chapter 19.
- Paper-Thin Disguise: Kanna saw through the Zombie Princess' disguise right away but didn't say anything because she doesn't see her as much of a threat.
- Parental Abandonment: Arima's parents are still alive, but they don't spend much time with her.
- Please Spare Him, My Liege!: Setsuna begs Kanna to spare Erionelle after Kanna beats her easily and is about to torture her for challenging a royal princess of the Oni clan by saying he felt Kanna was a Good Oni and didn't need to go to such extremes. It works. Moreover, Erionelle falls for him because of it, wanting to be a Good Oni for him, as well.
- Rank Scales with Asskicking: The Royal Princesses of the Oni clan are not only incredibly strong in their human forms, but their connection to the Royal Blood allows them to partially transform into actual demonic-oni and greatly increase their power. It is for this reason the idea of the Zombie clan being considerd as equal authority to the Oni clan is completely false.
- Rousseau Was Right: Setsuna certainly sees the good in many people, including Kanna, Rena, and Erionelle, as the formers never really cared about eating his heart to begin with, and the later actually wants to cure him of his condition.
- Royal Blood: The Oni royal family has a special one that allows them to tap into a deep power and transform if things get too rough.
- Talking with Signs: Rena just communicates by writing on her notebook.
- Tsundere AND Yandere: Arima. Alternatively stripping Setsuna, ordering him around, outright jumping him and refusing to admit to doing anything nice for him. It's kinda creepy.
- What Happened to the Mouse?: It's never explained whatever happened to Wakatsuki from Chapters 2-3, nor the restaurant owner that stopped Erionelle from chasing Setsuna in Chapter 18. After making the offer that starts the whole story, Middleman only gets mentioned once by Kanna a little while after her first appearance.
- Your Days Are Numbered: Despite the Unwanted Harem, Setsuna is reminded often of THIS and his bad heart condition would kill him before age 20 so this was in play BEFORE the deal, thus this story would have either a Downer Ending at worst or a Bittersweet Ending at best, making it an In-Universe Harsher in Hindsight.