An audiophile jumps to his death, meets something on the way down... and ends up crawling away from a pool of his own blood.
An unmotivated music high school student (our main protagonist) vs. a speeding truck meets the same fate in front of his friends.
Now those two must kill each other "in order to understand the joy of living", as proxy, with the power of classical music incarnated.

From AnimeWaves:
Touko's life seemed so ordinary, until she got that call... At the scene of the accident, by the puddle of blood, a young maid appeared... could no one else see her? And then, around the corner, a cry for help from a silver-haired boy... The veils are being lifted and the truth is being revealed!

From Japanzai:

In the edges of this world, demons known as "Pagans" lurk. Pagans are born when the souls of the recently deceased fall off the path to reincarnation. The reincarnation ceremony must be performed under moonlight, and so cannot be performed inside a city like Faith-Dehli, overly shrouded by both constant mist and thick smoke.

The Twanbach Funeral Service Company specializes in hunting these Pagans, especially those that attack while Twanbach delivers recently deceased bodies to the reincarnation ceremony—because there's nothing Pagans desire more than freshly dead human bodies with the souls still slightly attached.

Reginald, a 100+-year-old vampire who looks like he's 20, gets scouted by the Twanbach Company owner's mysterious twin daughters, Vanessa and Veroinica Twanbach. But first, they'll hunt Reginald a little, to see how far off the path he's fallen...

From MangaHelpers:
One day, Son happened across a woman, named Shue, that he had loved as an older sister when they were young. It looked like it was the same woman, with the same scars, but Son had thought she was dead. In fact, she was a reanimated corpse, resurrected by a young girl named Fuu to work as her minion. Son becomes Fuu's follower, determined to find a way to return Shue's soul to her body so that she might live again. However, Son doesn't know what he's gotten into with Fuu, though, as she ends up in conflict with many other practitioners of her arts, using Shue's reanimated corpse to do things that Son would rather have never seen.

Hika Souma, called Picasso by friends, is 17 and still without a girlfriend after being dumped 13 times. One day, a pretty girl who later introduces herself as Sujata drags him out from a moving train, and with her unwanted assistance, his childhood trauma toward demons (oni) takes the form of a real demon summoned out from his body.

This is oneshot of Tokyo Ghoul.

Japan is being invaded by parasitic gods. The only one left to stop them is Nakua, the spider god. She enlists the help of Taromaru, an otherwise normal boy who has the Nakua's spider familiar resting inside him. Together they free Japan's gods from the control of the parasites.

A short crossover between two manga from Ura Sunday - Mob Psycho 100 and Sekai Oni - drawn by the mangaka of Sekai Oni.

The manga consists of nine entirely separate short stories set in World War II, each reimagining a famous fairy tale with the European theater of World War II as a backdrop, often with poignant results.

(Source: Hokuto no Gun)

It's been 6 months since the L5 Campaign, the conflict that pitted humanity vs aliens with the whole earth sphere at stake; even thought at that time humanity joined forces as a whole and fought valiantly for it's survival, now that the true threat is gone the remains from old conflicts that have kept discord among people from even before the aliens arrived have started to resurface and thus the fight is far from over....

The ATX Team, one of teams that probed pivotal in the L5 Campaign have been "living their usual" being at the mercy of the chain of command and taking part in cleaning up the remainders from the DC war---- but little do they know that again some extraordinary events are brewing up; with the arrival of a strange lady named Lamia Loveless, who seeks help from the team and seems to know more about them than what she should, the path has been set, headed towards a chain of events that might bring forth an even greater conflict that the one from 6 months ago.... Can Kyosuke Nanbu and his team break through all of the opposing forces, yet again?

The storyline continues from several months after Weiß Kreuz Glühen. It follows Aya and Ken as members of an assassination team named Krypton Brand Side B in Great Britain. Weiß is no more. Of the original Weiß, only Ken and Aya have found their way into Side B.

Unfinished space science-fiction manga by Otomo Katsuhiro.

There are dangerous monsters called D's, lurking in the shadows of the world. A D mimics its victim's form exactly, allowing it to kill its victim and take its place. Kei, a normal high school kid, learns of these creatures when one of them targets his childhood friend Hinata. In his effort to protect Hinata, Kei finds himself being dragged into the affairs of Othello, an organization formed to bring about the extinction of these creatures.

In a world where demons have haunted humans since ancient times, Rose and Marie are on journey searching for their missing brother while at the same time following in his footsteps as a hunter

From Wikipedia
In the manga and anime, Tiger Mask (whose real name was Naoto Date) was a feared heel wrestler in America who was extremely vicious in the ring. However, he became a face after returning to Japan when a young boy said that he wanted to be a villain like Tiger Mask when he grew up. The boy resided in an orphanage, the same one that Tiger Mask grew up in during his childhood. Feeling that he did not want the boy to idolize a villain, Tiger was inspired to be a heroic wrestler.

The main antagonists in the manga and anime was Tiger's Cave, a mysterious organization that trained young people to be villainous heel wrestlers on the condition that they gave half of their earnings to the organization. Tiger Mask was once a member of Tiger's Cave but no longer wanted anything to do with them, instead donating his money to the orphanage. This infuriated the leader of the organization and he sent numerous assassins, including other professional wrestlers, to punish him.

Most of the environment and characters were fictitious, but real-life pro wrestlers Antonio Inoki and Giant Baba were included in the manga and anime as well.

From Easy Going Scans

Ever wonder what happens in the aftermath of a super hero and villain battle? Well someone has to clean up the mess, and they are called SHADOW.

Komachi Mizuno's family runs a shrine and a sword fighting dojo, but she doesn't like fighting and often skips out on practice. On Komachi's 16th birthday, she is mysteriously transported to another world similar to classical Japan.

A series of short stories that take place throughout the Universal Century Era.

A group of thirteen boys join the children's crusades of 1212. Violence ensues.

The story focuses around Makoto, a student who's talent is making stuffed toys. He starts researching the mysterious disease going around called 'Sudden death' after finding out that his latest creation looks like the mysterious stuffed rabbit rumoured to be causing it.