This is a fighting dōjin made with 2D Fighter Maker 95 by a single mysterious developer, Takase. Its development took no less than five years. The game's title won't mean anything to a westerner, but it's meant to be a pun (the Japanese translation of Les Misérables is あぁ 無情, Aa Mujō): It's a 2D fighting game, modelled on Street Fighter 2; the protagonists of Claude-Michel Schönbergof's musical (which is obviously based on Victor Hugo's novel) are the playable characters.
There's Valjean (and Robo-Valjean) with a devastating grapple, a generic policeman who is also the shotoclone of the game, Éponine with a very cheap slide kick, Cosette with her double attacks (as each time she kicks Valjean jumps in and kicks the opponent too), Marius with the ability to summon an army of zombies of the revolution, Javert with Akuma's moveset. There's also some sort of rabbit called PonPon, that has nothing to do with the novel and comes from some of Takase's youthful scribblings, who has infinite air juggle. Funnily enough, each character reacts differently to the opponent attacks, depending on their relationship in the novel.
Competently animated and with more than good character sprites, the result is very interesting and extraordinarily unbalanced: normal attacks are far too strong compared with special counterparts; when you're on the verge of death you have basically infinite power (exploitable until your life drops to zero); one of the characters in particular (Judgement, who looks like Yujiro Hanma from Baki) is far stronger than the others (in fact, he could win every fight by simply spamming a single attack).

If you want to try out all the characters, you should get the latest version. You can download It for free