Master of Martial Hearts was a 5-episode OAV anime series released from October 29, 2008 to February 25, 2009. The series was animated by Studio ARMS, who are well-known for creating Elfen Lied and a number of other ecchi titles, and is currently licensed in America by Funimation Entertainment for streaming and video release.
High school student Aya Iseshima comes across a brawl between two girls competing in a tournament for a prize called the Platonic Heart (Martial Heart in English dub) that will grant any wish to the winner of the tournament. Aya finds herself making friends with one of the two girls, a young priestess named Miko Kazuki, who chooses to retire from the tournament as her wish of making friends with someone came true. However, Aya finds herself placed in the tournament in Miko’s place. When the priestess is mysteriously abducted from her home, Aya finds herself competing in the Platonic Heart tournament against a number of fetish-themed women to learn of the whereabouts of Miko and the true nature of the tournament.
Originality is definitely not Master of Martial Hearts' best area. The series takes aspects of Ikki Tousen with its fan service and clothes-tearing fights with many aspects of the show’s plot being an excuse for said fights, even with the occasional hints dropped regarding the true nature of the Platonic Heart tournament. The fights Aya gets involved in involve women in fetish-themed outfits from their professions whose only roles are to pander to the title’s otaku audience and be punching bags to the female lead.
Master of Martial Hearts also takes a page from School Days’ book in trying to create an unexpected and shocking resolution in its final episode when Aya learns the truth surrounding the Platonic Heart tournament (which I won’t spoil here). While School Days made some sense with its shocking resolution with how hated much of its cast became from their actions (one of the few times you'll hear me praise the series for something), the revelations concerning the tournament for Master of Martial Hearts come across as poorly written and mean-spirited in comparison.
The action scenes don’t even work well in this title because of the subpar animation in Master of Martial Hearts. The quality and detail in the series looks more on par with a TV anime than an OAV and the action scenes weren’t too engaging or fluid as attacks from many female fighters tended to be themed for whatever fetish that the fighters stuck with and shortcuts with animation were quite notable. Also, don’t be too surprised if you see a change in the bust sizes of Aya and Natsume as they tend to switch quite frequently between being normal-sized and huge.
Might also want to avoid listening to Master of Martial Hearts' opening music as it makes for quite the obnoxious and irritating little J-Pop song.