Kindaichi Shounen no Jikenbo (TV)

Kindaichi Hajime may look dumb, but he is one of the smartest you will ever see. He encounters mysteries after mysteries with his good friend, Miyuki, and he swears to solve them in the name of his grandfather, which was a great detective. (Source: Anime News Network)

Yu Yu Hakusho: Ghostfiles

Urameshi Yusuke, 14 years of age, is about as troublesome and violent as teenagers come. He is constantly ditching school, causing trouble, and getting into numerous fights everyday. One day however, he does the unexpected, sacrificing himself to save a young child. Such an action, was never ever expected, especially coming from someone as troublesome as Urameshi Yusuke. The afterlife is not prepared for Yusuke, as they never thought he would make such a sacrifice. Nowhere to go, and dead, Yusuke becomes a ghost and must earn his way back into existence. Yusuke is "employed" by Koenma, who is in charge while his father and ruler of the afterlife, King Enma, is away. Under Koenma's command, Yusuke helps to stop menacing demons that threaten the lives of people everywhere; whether by stealing priceless and invaluable items and destructive weapons, or by wreaking havoc on humans everywhere. Throughout Yusuke's journey, he is usually joined by; his arch-rival, and local bully, Kuwabara Kazuma. He is also joined by two demons named Hiei and Kurama, whom are ex-convicts of the afterlife that managed to escape from Koenma. This group of unlikely allies goes on to participate and struggle in battles that have outcomes that determine the fate of humanity! (Source: AniDB)

Black Jack (TV)

Black Jack is an "unregistered" doctor with a clouded, mysterious past. He works with his little assistant Pinoko (who has a massive crush on the doctor), dealing with medical cases not very well known, which can be strange, dangerous, or not known at all. But he is a genius, and can save almost any of his patients' life (as long as they have the money for it, that is), and is known to many around the world, especially to those of medicine and science. He's a man of science himself, and does not believe much until he has seen it, yet it is many times he is surprised by love and nature often overpowering the science he bases his life in. (Source: Anime News Network)

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Watanuki Kimihiro can see spirits and other assorted supernatural creatures, which is quite a bothersome ability he strongly dislikes. On the way home one day, while plagued by some spirits, he is inexplicably compelled to enter a strange house. There, he encounters Yuuko, a mysterious woman who claims to be able to rid him of the ability to see and attract the troublesome creatures – for a price. She demands for him to work at her "store" that grants wishes to people, and thus begins Watanuki's adventures through weird and wonderful events.

Parasyte -the maxim-

They arrive in silence and darkness. They descend from the skies. They have a hunger for human flesh. They are everywhere. They are parasites, alien creatures who must invade–and take control of–a human host to survive. And once they have infected their victims, they can assume any deadly form they choose: monsters with giant teeth, winged demons, creatures with blades for hands. But most have chosen to conceal their lethal purpose behind ordinary human faces. So no one knows their secret–except an ordinary high school student. Shin is battling for control of his own body against an alien parasite, but can he find a way to warn humanity of the horrors to come? (Source: Del Rey)

Nura: Rise of the Yokai Clan

Rikuo Nura appears to be an average middle school student. No one knows that he comes home every day to a house full of youkai, nor that he transforms into the all-powerful leader of these spirits at night. However, much to the disappointment of many, Rikuo is determined to live as normal a life as possible.