If you liked the Judge anime, the Anime-Planet community thinks you'd like:
At Count D's pet shop, you can acquire any form of animal, from an ordinary canary, to more.. "exotic" creatures. Made to sign a contract before purchase, Count D claims no "responsibility for actions incurred" if the purchaser does not follow its instructions completely, as results can be fatal. Patrons of this shop are able to get the rarest of creatures, but often, their purchases are coupled with demons from their past that won't go away easily.
Pet Shop of Horrors and Judge are tales of horror and justice. There is a certain creepy factor contained in their episodes that is very similar.
If you enjoy grim tales of poetic (and supernatural justice), you should give these a try.
Koshigaya and Komada are professors by day, but at night, they are Bio Hunters. Their mission? Hunt down people infected with the ellusive Demon Virus, and destroy it. Things become complicated when the two become entangled with the fate of Sayaka, a woman whose grandfather is a famous psychic. With powerful enemies on their trail, they must find Sayaka's lost relative to hear his prophecy, or die trying!
When evil overtakes the heart of man, it destroys his soul, changing him into a hideous creature of flesh and darkness. And where there is evil, there are Hyoi and Ryoi Kagezaki, humans who can morph into cats, known as the Dark Cats. In the present, a great evil is manifesting in a local high school, leading Ryoi and Hyoi to enroll and investigate. But the source of the evil may not be who they might normally suspect, and the consequences of the discovery may very well be deadly...
Has someone done something to hurt you or the ones you love? Are you seeking revenge? Rumor has it that there’s a website that can service your needs. Titled “Hotline to Hell”, it contains a form that can be accessed only at midnight. Type in a name, and the Hell Girl will carry out your bidding – for a price. For though your appetite for revenge will be satisfied, your soul will also be condemned to hell after you die. But who is the Hell Girl, and does she care whether your revenge is justified? Apparently not, as long as she gets more souls…
Both Judge and Hell Girl delve into the topics of supernatural justice/revenge. A theme they both use heavily is the concept of not being able to escape one's sins.
Hell Girl is longer, and thus has time to develop a fuller story, but I am confident if you enjoyed one, you will like the other.
It is believed that to consume the flesh of a mermaid, means that you will never show signs of age, and live forever. However, many cannot handle its taste and become demons for eternity. Towa is a woman whose thirst for this flesh consumes her, as she was made only partially immortal by drinking the blood of a mermaid years ago. Unable to cast her demons aside, she destroys everything in her path on a search for this legend.