"Let's go together! To Japan!!"
While he was traveling in Central Asia on the Chinese server, Leonardo was dropped into the city of Tekeli that is impossible to escape. Among the worst of circumstances, a savior appeared...
From Log Horizon, the story of another one of its heroes, Kanami, now begins!!

Despite the title this manga has nothing to do with sex, just young people rebelling against the world.
The manga is about the adventures of a girl, Kaho. In the first chapter she goes on holiday to Okinawa and starts following around Yuki, a car-stealing punk.

From An Endless Story:
Popular stories from fashion magazine Zipper have made their way into a special book.

Letter by Hazuki Kanae
"Who are you?"
On a certain day, she discovered a letter left in her school desk...

My Best by Fujisue Sakura
"I can't touch him, because we are friends."
Where will these unsuppressable feelings lead us...

Miss You by Kumiko Saiki
And the day they part ways finally arrives...

Goodbye, I'll See You Tomorrow by Tomoko Noguchi
Yasaki, who finally gets a boyfriend, now has to enter into a long distance relationship! Even though she thought that the pain of not being able to see him was the same...

CHERRY by Matsumoto Nanako
The only person that would suit her is someone as extraordinarily popular as she is, right!? The person in question should definitely be...

To the You Who is Here by Haneda Ibuki
Does she still seem like a child to her older boyfriend?
All she wants is for him to glance her way...

Collection of Nishida Higashi's debut oneshots

Yuzuki has always had an unrequited love towards her childhood friend Junya, but one day Junya starts dating his classmate Kaori.

Yuzuki was shouldering the pain that she would never be able to express her feelings to Junya. A while back, she had noticed that Toshiki was looking at Kaori with such a sorrowful expression. In order to obtain the paradise that she desired for, she decided to become accomplices with Toshiki but…!?

Contains a short story named Hatsutaiken:

Araki is dating Arashi but she has a secret from her past that she doesn't want Arashi to know. Will she be able to keep it a secret?

Frustrated that no one believes her, in order to capture a serial killer, a mind-reading detective teams up with the head of the "occult division"... who's a lot younger than she thought.

Includes 1-2) Iyayo Iyayo mo Kiss no Uchi 3-4) Start Line Made Ato Ippo. 4.5) Iyayo Iyayo mo Kiss no Uchi Extra Chater

It was later released in the "30th Aniversary - Ay", a special book.

From Friendship Scans:

In the history of the Kingdom of Siegerland, there has always been a powerful Shadow Messenger who acted as a guardian for the country. Yet the Shadow Messenger himself doesn’t have a shadow!
Every Shadow Messenger chooses a guardian out of all the knights. In order to show his devotion, the knight then offers his own shadow as a gift to the Shadow Messenger and by that becomes a Swordsman.

Lisa is a normal girl who leads a happy life like everyone else, when suddenly her father dies a tragic death. From that day onwards, her mother forbids her to leave the house. In the end, she secretly steals away with her childhood friend Louis. They are playing outside, when her playmates die under strange circumstances… Only Lisa survives, but she lost her memories of that day...

Volume 8-9 is a special one, as it talks about Rapunzel's side story.
This is an additional volume called Koori no mamono no monogatari Gaiden, which is an anthology of short stories featuring different protagonists of Koori no Mamono no Monogatari,

From Rebellious Love:
A cute short story about a girl who's a tomboy, but whenever she's around him, she seems to turn girly.

Nomura Nobuo was a normal highschooler, until his "gift" convinced him of his separation from the masses. When his gift is unmasked by Kaburagi Jirou, it marks the start of a war. A war on society itself. The War Front: Spike Hills.

From Stage Storm:
This manga includes four different stories dealing with horror and supernatural stuff.
1) Constellations that Sing of Death
2) Mist When You Turn Around / When the Fog Comes
3) Shiver of Flames / Fire Starter
4) The Mansion of Time / The Castle

Yunogi has no working experience, but after being tricked into thinking he got a normal job out of luck, it turns out it's not so normal after all. Yunogi has to act as horror writer Kirino Shuusuke's dummy (i.e., stand-in).

Izumi Wakakusa is a renowned actress obsessed with beauty. When a hideous mark shows up on her face, she suddenly disappears and gives birth to a little girl: Sakura.

Sakura is always pampered and overprotected by her mother, until the day that she discovers why she was born.

Fujinami Kou is a high-school second-year who had lost his boyfriend, an upperclassman schoolmate, to a car accident an year previously. On the anniversary of Misumi senpai's death, Kou is dispirited and contemplating skipping school. Kakitsubata Saki, a first-year, sees him and offers help, assuming that he's ill. As Kou startles at the sight of Saki's face and mentions that he resembles "the person I used to go out with", the younger boy is instantly intrigued and resolves to discover his sorrowful, introverted upperclassman's secret.

The demonic overlord has been revived, and kidnapped the beautiful Princess Sina. An army of the world's finest knights has been sent to his castle to rescue her, but Sina refuses to be a mere damsel in distress and decides to break free on her own.

Say hi! This is Nika Novikova. She's 17 and she’ll soon finish school. Her parents died in a car crash a year ago, leaving her the heiress to the enormous film company "Ranco", which will be under her caretaker's direction until she comes of age. Nika is beautiful and smart, she studied martial arts - and, one day, she’ll have to put all of her talents to use.T/N: This is a Russian manga, published 1998-2002. It has a total of 5 chapters (~250 pages), plus a standalone, shorter, release.

From Hana-mi:

This series is adorable. And occasionally freakish and violent. Mutsu Kokonose, a tiny exorcist and holy terror, crash-lands on a mythical island where the fairy tales are real...

Nanako Kobayashi, a 17-year-old teenager, has an ugly face who seems to not have a care for the world. One day, she got a call, only to be given two choices to answer a question. A devil suddenly appears, taking the form of her teddy bear. The devil is willing to grant her three wishes; each based on two options; What wishes will Nanako choose?

[From Ushi]:

"Once upon a time I dreamed I was a butterfly,
fluttering hither and thither,
to all intents and purposes a butterfly.
I was conscious only of following my fancies as a butterfly,
and was unconscious of my individuality as a man.
Suddenly I woke, and there I lay, myself again.
Now I do not know whether I was then a man dreaming I was a butterfly,
or whether I am now a butterfly dreaming I am a man."
-Chinese proverb from 3rd century B.C.
(Zhuang Zhou Meng Die (庄周梦蝶 ))