The story of the "sweetie-horror" manga begins when an unnamed character without memories gets lost and arrives at a mansion. There he meets Charon, a naive girl who has a secret.

A a variety of oneshot stories related to the supposed end of the world in 2012.

5) Nature-0 by HEE-JUNG Baek
Resource depletion, environmental contamination, desertification, and foolish wars. Mankind willingly walked along the path of annihilation. And at the end of that path, those who survived relied on the power of science and conducted endless experiments to obtain the valuable source of life. As scientists are exploring the desert's fallout areas, a child-like being is found naked on the ground and was brought into an underground survival refuge. As they analyze the child, what will they discover?

8) Myum-Myum by currygom
The world is in an uproar over the discovery of a stone tablet thought to have been created 500 years ago.
The stone contains predictions of major incidents that happened worldwide in the last 500 years. All of its prophecies had already come true. There is only one prophecy recorded on the stone that pertains to the future ahead: that the world will end in a year?s time, and only those who believe in the god drawn on the stone will find salvation.
The name of this god is... Myum-Myum.

13) If the World Ends, That's Cool! by Rangto
Friday the 24th, August 2012.
The world will end due to a meteorite crash... tomorrow. But people are fine with it. No one is screaming. No one is praying. Because they are all... cool.

From the manga habit:

Rio is a 14-year-old boy with no particular special traits, except his burning love for books. He's awkward and considered odd at best by his peers. Rio also has a twin brother, Mao. Although they look alike, they couldn't be more different. Mao is good at everything, is popular, and has future plans to have a big, happy family. Despite their differences, the brothers are close.

One day, when Rio attempts to retrieve a cat that wandered into the street, he is hit by a car right in front of his brother's eyes. Everything fades to black. In the darkness, a voice offers a choice: to live or to die. Fading rapidly, Rio gives the obvious answer: to live!

Rio awakens in a world filled with foreigners and strange animals he's never seen before. That's not the only odd thing–Rio now has the form of a black cat! He quickly learns cats are revered in this world because of their special role as familiars of wizards.

From ShoujoLove:

The one Mitsu likes is the class' #1 popular guy, Ryuuzaki, but she always pretends to hate him. But, more than anyone else, she wants to get near him... All of a sudden Ryuuzaki kisses Mitsu! Is he serious? Or is he only teasing? This bothering her, desperate Mitsu confesses to Ryuuzaki!?

From Midnight Scans: Miu is living with her dad since her mom left them some years ago. While taking care of the house, Miu has missed the breaking news about thet new transfer student. When she meets Keita at school, he seems to know her quite well, but she doesn't recognize him at all. Who is Keita and why is he approaching Miu so openly?

From Mystic Iris:

For Mizuki, her life turned for the worst when her long-time neighbor and tormentor Ryohei joined her high school as a student teacher. Now she can't seem to catch a break from him in school nor at home! What can she do now that this sadist keeps leading her around, making her day to day life a living hell?!

Sui is an actress who has just debuted, but she only took on roles as either vengeful spirits or evil supporting lead. Although her goal is to be the top actress in the industry, Sui has a fatal weakness --- that is her fear of men (androphobia)!!

Sui was offered a chance as a leading role in a new romance drama. It's a great chance for Sui but it's fully loaded with lovey-dovey scenes. All the touching, kissing, bed scenes were driving Sui crazy! In order to succeed, Rihito (Sui's new manager) spent 3 days 3 nights to research on treatment of androphobia. Sui, touched by Rihito's perserverance, determined to work hard for his sake. However, would she be able to interact with men naturally?? And her feelings for Rihito...

Included side stories: 保健室のヒミツ (保健室的秘密), 恋なんかじゃない!? (这不是恋爱吧!?)

(by ice_blossom)

1 Volume, 5 short stories:

1) Hitomi de Watashi wo Tsukamaete
To try to find out if her boyfriend loves her, Nanao rejects love-making.

2) Love springs from dreams of hope

3) The revolution of the sleeping beauty

4) The night of two people embracing

5) The infatuation that never ends

Kyoko had planned to confess to Kenta, only to hear from him about his crush on a close friend. To stay by his side, Kyoko can only hide her feelings and act as Kenta's love advisor...

Also includes 2 other short stories.

Heureka is a manga set in antiquity, during the Second Punic War between the small city state of Syracuse and the Roman Empire. The comic is based around the life and times of the famous mathematician Archimedes.

Archimedes was not only a gifted mathematician but also an engineer of repute. During the conflict with the Romans, Archimedes was supposedly responsible for creating a number of war machines that devastated the Roman legions before they eventually got the upper hand. The exact nature and use of these devices is controversial, and exists more in the realm of legend than actual historical fact.

1. Dakedo Happy Paradise ~Side Story~ "Anyways Happy Holidays"

2. Angel Love Song
Mizuho is a young girl who just had an argument with her boyfriend, Kei-chan. On the way home, she met a guy with a guitar from the greenhouse who called himself Tenshi. Mizuho took him home and asked him to form a group for the competition to win a cruise dinner so she could make up with Kei-chan. So will Mizuho get back together with her boyfriend, or will something else spark? It was also included in Bloody Kiss v1 tankoubon (2006).

An anthology of oneshots. 6. Advent Prince - Karen is in love with the school Prince. When he asks her out it seems too good to be true. Why is he interested in her?

From Fallen Syndicate: By using the Dark Gate, humans can entrust their hopes and needs to the darkness. The darkness they call upon is a great and evil power, known as "Demon." WIth the help of his partner Miroku, the Demon Slayer Kisaki Senju will slaughter every last "Demon" that is called into existence.

This is a volume of short stories that are all related by their setting, which is a (めがねコーヒーショップ ) ‘Megane Kissa’ or a coffee shop that features cute waiter boys who all wear glasses. Each story is about a different girl finding love with one of the glasses-wearing, super-cute bishounen waiters while engaging in various smutty acts along the way.

From Manga Mania~ On the day Sari transfers to her new school, she confesses her love for her cousin Kazuomi. After being subtly rejected, she find out that Kazuomi's best friend Mizuki is also interested in him. Because those two are like the sun and the moon, Sari's determination to be Kazuomi's girlfriend begins to waver. How will this interesting love triangle develop?

Tcmanga
..............
My name is Aya Hojo, and I am a little foolish high school student. My boyfriend, Kei Saeki, is the smartest and most handsome guy in school. A genius and a fool in love. The comics included are "Genius with Glasses" and "Genius is in a Bad Mood."

From Storm in Heaven:

A series of romantic short stories drawn by Sahara Mizu and inspired by the music of the Japanese band Sukima Switch. Each chapter is inspired by a different song.

It is the year 1999. In Nagano Matsushiro stands the pyramid of Japan, the private Voltstein Academy.

This place is famous for repeated occurrences of occult phenomena within its premises. Hence, it is also called the Occult Academy. The dean is committed to studying the occult, while the students are zealous in their everyday schoolwork.

One day, the dean passes away and his occult-hating daughter, Kumashiro Maya, visits the academy. There, she meets a self-proclaimed spoon-bending "time agent" from the year 2012, Uchida Fumiaki. As the two encounter various bizarre phenomena within the academy, the reason for Fumiaki's timeslip to 1999 becomes clear.

All Arisa wanted was to go overseas for the summer, but instead she found herself roped into an Omiai with the heir to the Narimiya Corporation. She doesn’t want to be involved in this and is trying to find a way out, but Narimiya has decided that he wants to marry her – and actually has the romantic skills and determination to win her heart!

-- Onigiri Gakuen

Chapter 7 - A girl becomes the comfort sex friend to a playboy that she secretly likes and hopes that one day he will see that she's all he really needs.

From Divine Sanctuary:

My husband is my homeroom teacher. Is there anything else to tell...