Since there are only two roughly half-hour episodes, there’s not enough time to adequately develop the characters, either. The main character, a ninja named Hikage, shows little emotion throughout the series, and rarely talks about what he’s thinking or feeling. His interactions with other characters are brief, limited and sometimes awkward. For instance, in the second episode, he berates a female ninja named Aya for crying, twice. He also acts uninterested in her, but for some reason she falls head-over-heels in love with him. His establishment as the antagonist Marou’s best friend is relegated to repeated flashbacks of the two running through a field as children. Supporting characters get even less development, which results in the viewer not caring what happens to them.
Background information which would help explain the plot is either not included or glossed over. This includes what exactly the “Youma” are (I get that they’re literally demons, but it’s not really explained what they are in this story’s universe), why the two Youma rulers of the land and the sea have to combine in order to unleash all of the Youma, why the Youma ruler of the sea is a horse, and other issues that could potentially be spoilers. Also, the whole premise that kickstarts the plot, where Hikage has to chase after and kill Marou, is not explained well. Basically, the ninjas’ “master” is killed, and according to his will, they have to hide his death from the public for three years (why?). Since Marou has gone rogue, Hikage is sent to silence (kill) him to keep the secret safe.
Also, contrary to what the synopsis on MAL and other places say, Marou was not killed in battle and resurrected to serve the Youma, but explaining what he really is potentially goes into spoiler territory, so I’ll refrain from elaborating.
True to its English title, there is plenty of bloodshed in this OVA. There is also a lot of grotesque body horror, with beheadings, disembowelments, monster transformations and whatnot, but it's not as off-putting as similar scenes in other anime are. There is no nudity in “Youma,” save for a naked baby boy at the very end.
As for technical aspects, the animation and art are serviceable — not bad, but not amazing, either. Characters' reactions often aren't realistic, and sometimes seem to come at the wrong time (like too early). Occasionally characters say things, but their lips don't move. The voice acting is okay. Kaneto Shiozawa particularly stands out as the voice of Marou. Background music varies between traditional Japanese-style music and ‘80s synth-pop. The ending theme is in the vein of the latter, a catchy, upbeat synth-pop track that, while nice, feels thematically inappropriate. There’s a pleasantly haunting insert song, but it doesn’t connect to the plot well (or if it does, its connection is not explained).
Overall, this OVA could have been better if it had had more time to flesh out its plot and characters. It tries to cram too much into a roughly one-hour runtime, and suffers as a result.
