In the 80s, Kaze Takashi's parents moved to a quiet area in Tokyo to protect their son from the bad influence of his friends. In class, Takashi doesn't wait to make new friends. Passionate for motorcycle rallies, they invite Takashi to join the next event. It became a revelation for the young man and he decides to join a biker gang! Now all that's left is to find a motorbike...

From MangaHelpers:
While looking for a ghost that helped him as a child, Satou Akira has run into a fair amount of spirits that he doesn't even see. One day, he goes to a supernatural detective agency for help, and he meets the adorable Yui and her devoted butler Kujou. Using her power, Yui ends up helping him with a number of the dangerous supernatural troubles he gets himself into. Akira starts to feel attached to the detective agency, and wants to learn more about the supernatural.

This was released quite a bit before the aforementioned series was serialized and features prototypes of the Supervisor and Maid characters.

'Creepy Side', is a creepy and eerie neighborhood. A series of tragedies mixed with black comedy in this town begins!

The world is under attack, from huge unidentified floating objects. The first attempts to stop them have been unsuccessful, some soldiers have deserted to go home to enjoy their family time.

7 heroes show up to fight the unknown threat. They fly up in the sky in a glow of light while they are enveloped in big robot frames.

Is this the time for Souya to join the heroes in a fight for humanity?
No, apparently he has to fight off the heroes.

A battle between gods and demons rage on in the mortal team, if the waifus are unsatisfied, how could the world stay peaceful? “Wait! Stop! Stop trying to lick me!”

"What do you mean we couldn't get out from the Kotatsu!"
Four high school best friends in their early thirties gathered in the apartment for the first time in 10 years. The night is indeed perfect for some girl's talk under the warm kotatsu table. They were only talking about beautiful memories, but why suddenly they have to deal with this paranormal phenomenon?!

Saito lives in an apartment full of spirits until a priestess randomly shows up claiming that she's going to protect him, but usually does the opposite and he ends up worse.

Set in a ruined world overrun with chimerical creatures where the female creatures eat the males. Two creatures explore the land: Usagi, the elder sister, protects her brother Mitsuki, a curious chronicler who is able to read the books in their secret hiding place to know that the world was once different.

"It's only me who can see them."
His distorted love eventually caused the murder of the brother, who had been seeing an endless nightmare...

Two high school friends, Rie and Keiko, usually commute with train. But this time, suddenly there was a strange announcement, and the train was shaking a lot. Before they know it, everything has turned darker--"It seems like we are in the parallel train."

When a ghost appears that only Noah can see, he turns to his Aunt Alice for help. She is the Cornfield Witch, after all.

His love for the otaku culture led Italian Mingo to Japan in a quest to find a Japanese girlfriend. However, to maintain his lifestyle, he has to become a model. In a place where Italians are supposed to be popular, how could our low-esteemed otaku amico fit in? A cultural exchange comedy from the Italian Terrace House Tokyo 2019-2020 member Peppe!

Based on the game of the same name, this manga takes the events from the game and puts them in the point of view of the heroine(s) Touko Fukawa and Genocider Syo!

“Twitter” is a web service that is extremely popular all over the world now posting and sharing short sentences with 140 characters or less. And this is a rumor...there seems to be a humanoid interface to observe users and develop functions in order to improve the contents of the service more. This girl is called “Twitter-san”.

The story follows the daily life of Sayoko Nanami, a 25-year-old woman that loves hot baths and wants to try and visit many different types of baths.

Neiko Futaba is the school idol, but little does everyone at school what's she's really like. Only her beloved younger twin brother Otohiro knows her overly clingy persona, much to his dismay. On top of that, it seems Neiko seems to be rather determined to seduce her brother in every way possible. Unfortunately (or fortunately) for Otohiro, it is just an everyday occurrence in the Futaba household...

From MangaHelpers:

This is a story set in the dangerous Sengoku period, featuring the famous historical figure of Takeda Harunobu, later called Shingen. When he was fifteen, he accompanied his father to the Battle of Un no Kuchi, where he won his first victory as his father retreated. After that, his relationship with his father, Takeda Nobutora, changed. He heard rumors that his father wanted to give his inheritance to Harunobu's younger brother. Soon, Harunobu became certain that he must do something about his father...

When Suzuki Oji enrolled into high-school, he was hoping some kind of excitement would fall into his life -- but he never expected it to take the form of Kuromori Kisaki, a descendant from a 400-year-old clan of witches! However, Kuromori needs a special brooch in order to fly on her broom, something she lost when she landed on Suzuki after he had mistakenly thought she was falling to her death.

Although he initially thinks Kuromori is being unfairly difficult to socialize with due to her "witch" status, he finds and returns the brooch to her. Out of gratitude, she shows her magic to him through the use of her broom. Suzuki then questions the possibility of himself flying by also wearing the brooch, but right after Kuromori pins it to his coat, both of them suddenly find themselves several feet in the air before falling into the school's swimming pool! Just who or what is Suzuki...?

Munakata is an anthropology professor who studies the relationship between folklore or fairy tales and real historical events. He believes that many of these stories that most presume to be entirely fictional are actually based on real events. This manga tells the story of Professor Munakata as he follows the clues left from both the imaginary world of fairy tales and the real world of historical evidence.