Summary by Ressey101:

This oneshot involves the Drama Club's President Yuki-chan and her best-friend Saori-chan. A very energetic Saori, reminds Yuki why she became the Drama Club's President in the first place.

In the hopes of pleasing his childhood friend and crush, Chiharu, Arata agreed to help her clean out an old warehouse from her grandfather. But what neither of them knew was that the warehouse contained "tsukumogami", ancient objects imbued with life. When Arata accidentally broke the seal on a box containing an artifact that hungered for vengeance against humanity, Chiharu was kidnapped! Now it is up to Arata and the good, loyal artifacts to rescue Chiharu before it is too late!

Hundreds of millions of years ago, highly-advanced beings looking to make a planet for themselves purposefully tampered with Earth's natural processes in order to create multi-cellular life. Watching the planet's evolution closely, they continued to help life evolve further in the hopes of having actual civilization develop.
It's now 1996 in Seoul, where Hyesong, a high-school student, struggles with the usual problems of youth. The only unusual thing about him is that he's been having the same apocalyptic nightmare for an entire month; in the dream he is an great fighter and genius tactician who faces off against a seemingly-unbeatable foe.
Are these dreams not really dreams? Does he really have a role to play in the cosmic balance of the universe? And is the new girl in his class really just a normal student?

From back of book:

He-Sung has dreams of the Earth being destroyed by alien invaders! In these dreams he is a motorcycle-riding warrior, the last defense against the alien armada. By his side is a beautiful armor-clad girl with strange powers and futuristic weaponry. But these are just dreams, and they don't mean anything... right? That's what He-Sung thought... until his mystery dream girl appeared as a new student in his school! But if she is real... can the aliens be far behind?

1) 先輩の原稿ボックス (Senpai's Manuscript Boxes) 2) レストランベルへようこそ！ (Welcome to Bell Restaurant!) 3) 超能力学園メッサイケメンズ (ESP Gakuen Messa Ikemens) 4) 水の街の童話 (Fairy Tale of the City Water) 5) リボン・プリーツ・オトコノコ (Ribbon Pleated Otokonoko) 6) The sky, the rooftop, and you - Kamikou Chizu 7) 某日、試練の日 (Certain Day, Ordeal's Day) 8) 八城の決闘 (Yashiro's Duel) 9) 花の王子様 (The Prince of Flowers) 10) BBB★Junk 11) 「チェンジフレンド」 ("Change Friends") 12) 身代わりっ！ (Scapegoat~!) 13) 花摘み少年 (Boy Picking Flowers) 14) びっくり！ (Surprised!) Used translation software to translate titles.

Collection of oneshots, the majority of which are extra of the author's other works.

1) Your Word Is my Command (Aruji no Oose no Mama ni)
Nanjou Hiroaki always finds himself unconsciously taking care of others. But soon, he becomes conflicted and guilty when he realizes that he has grown to rely on his underclassman Asouzu...

2) Seppun Kindan Shoujouchuu
Student council tagalong Takafu is used to being close to his friend the president, but it's underclassman Niyuu who keeps kissing him! Can the super dense Takafu figure out why he's suddenly so irresistible to the younger man?

3) Fujino-kun's Revolt [Electric Hands Extra]

4) Ootsuka Family's Weekend [sequel to Brothers Battle, third story of Electric Hands]

5) Higan Tassei hi [Damarashite Katarazu Hitomi de Otose Extra]

6) Jinsei Kouro [Renai Yuugi Extra]

7) Zipped Open [Koi wa Ina Mono Myouna Mono extra]

8) Koi wa Ina Mono Myouna Mono [extra of the release of the same name]

9) F no Higeki (Tragedy of F)

10) I got some business [Your Word Is my Command (Aruji no Oose no Mama ni) extra]

11) I'm not letting you go [Seppun Kindan Shoujouchuu extra]

12) Birthday Present [Koi wa Ina Mono Myouna Mono extra]

Yuuto is an ordinary run-of-the-mill high school student. But one day he gets struck by lightning, and things start to take a turn. A strange person, who goes by the name “Kazuchi”, shows up and starts following Yuuto around. Kazuchi turns out to be a ghost with mysterious spiritual powers, and proclaims (insists!) that Yuuto is the reincarnation of Princess Aki from a thousand years ago. Now, Kazuchi won’t leave Yuuto alone until he remembers who he really is!

From DMP

From JShoujo Scans:

Hiraku's a slightly moody college student who's been having a hard time getting used to his new big-city life. A flamboyantly gay guy's latched onto him like a leech and follows him around wherever he goes, and a girl who he had a one-night stand with comes up to him telling him that she's pregnant and demands money from him so that she can go and get an abortion.

Amidst all this chaos, one glaring question crystallizes in the minds of all those around him ---who is it that he really loves?

From ShoujoMagic:
Rieko Edogawa is a second year student at East Edogawa Academy - a private school. She is full of energy and courage, and she is so popular that there is not a soul in her town or school that doesn't know her. But Rieko's one weakness is Teppei Sakamiya, her childhood friend. She has liked him for a long time, but Teppei can only see her as a good friend. Meanwhile... Naoto Akutsu, a transfer student, appears...

From Ryuusei no Mafia:

Minnie’s the only human living on an alien planet and because of that she’s rejected by almost all the other inhabitants. Then one day something falls outside of her house and it happens to be... a human prince?!

Minori is the manager of her high school's baseball club, which has been defunct up until five years ago. Even now, it's a little rough, since there currently are no seniors in the club at all! None of the second year players know why the club closed so many years ago, or about the baseball history all their fathers share...

After dating a player who had another girlfriend, Rina decides to become a player also and immediately finds someone willing to be her lifelong toy.

From Reverein Scanlations: A series of short stories featuring two characters with the same name, Asuka Koji and Takaki Asuka. They both have super powers and share a common love: SAKE! This really has no real plot but it provides a lot of entertainment and random characters from her other works also appear.

The protagonist is your average, everyday, Korean school student. That is, if not for his obsession that aliens live on Earth disguised as humans.

Much to his surprise, he was right, the aliens play a game called "Avatar" where they take human form and live human lives. And because of a glitch he caused in their system, now his very life could be at risk.

Now he needs the protection of an Admin of the "Avatar game" or else he could very well die!

From Wikipedia:

The story is about Kozue Ayuhara, the new girl who transferred to Fujimi College, who tried out for the school volleyball team. Her friendship with Midori would develop, and her talents would impress coach Honga more and more each day. Though she showcased extraordinary volleyball skills, she would make enemies with Yoshimura, the star of the current team. Kozue would discover that being at the top would bring stress, incompatibilities and other dilemmas into her life. Her high expectations of becoming the best volleyball player in the school, Japan and eventually the world, would set the tone for the drama to follow.

From Del Rey:

Since ancient days, the Gaius School of Witchcraft and Wizardry has trained the fiercest swordsmen and the most powerful wizards. Now one boy could become the greatest of them all. If he studies hard. If he is true to his friends. If he believes. And if he survives…

This manga takes place a few years after the two lead males have graduated from high school. One of them came out in high school, and the other was a scary senpai who kind of took care of him. But now they meet at the same office, several years later, where the kouhai has yet to come out of the closet...

Fukaya Shinichiro's whimsical grandfather has decided, quite out of the blue, to hand over one of his many holdings, a bookstore known as the "Fukayadou", to his high school-age grandson!

Shinichiro is understandably reluctant, but when he sets foot in the store only to be immediately drawn into a world full of fantastical books that thrive on human emotions, and meets the handsome blond man with a mysterious smile who works as its manager, he realizes his life will never be normal again.

Gag-Comedy

Tsubasa Nonomiya transfered to a new school because she wanted to be the manager of the boy's basketball team. When asked, she claims to hate basketball. So why did she transfer schools? The answer: Takaya Misaki. Who happens to be on the school's soccer team, not on the basketball team. *From: Baka Updates*