Quoted from 4dawgz (the scanlator)-
"So there's a magazine called Gelatin where various manga artists are given some coloring crayons and then told to draw whatever they want in full color. The plot for this is about a guy and a girl who go on a mission to retrieve a pair of shorts from an island... aaaaand that's it. All you'll find is a nice slice-of-life story and lovely colored pages."

Nanami Sekai gets scammed out of every penny he has, left only with a pair of boxers and a 3,000,000 yen debt. He then meets a girl, Ritori, who offers him a deal that seems too good to be true: she will take care of his debt if he will be her captain and help her with her job.

[Note]
It seems that this manga has been discontinued because the author became incapacitated during serialization and was not able to keep 2 series running.

One day, cute little Tarepanda decides to go on an adventure. But after a few bad turns, he realizes he misses home. Will he find his way back? Or will he stay lost forever?

This little one-shot is simple, charming and cute. If you like sweet slice-of-life / adventure stories, do yourself a favour and go read it!

From Tokyopop:

Having been assigned by the human elders the mission of stopping a mystical plague that has afflicted the Youkai with madness, Genjyo Sanzo assembles his team of Youkai warriors, desperately hoping that the disease will not affect them. He sets up qualifying tests that will help him determine the loyalty and worth of Cho Hakkai, Son Goku and Sha Gojyo. The team then journeys west to rid the land of madness.

The continuation of Slayers Revolution. After the defeat of Zanaffar, Lina, Gourry, Zelgadis, Amelia, and Pocota, the prince of Taforasia, continue their hunt for Rezo’s urn, each with their own motivations for doing so. Pocota to revive his people from Rezo’s well-intentioned sleeping spell, and Zelgadis to regain his former body. However, something deeper is circling around the intrigue behind Rezo’s urn, and all will come to a head in the bustling city of Vezendi...

The demon queen subdued enormous and powerful monsters and slaughtered over half of the world's population. Surviving members of the human race elected a hero to slay the demon queen, beseeching release from her oppressive rule. However, he questions his mission to eradicate the monsters: in his opinion, they too are conscious and alive, and so he anguishes over that fact. Sheila the Demon Queen became interested in him and joined his journey, hiding her identity and with the plan to kill him after she has gained his trust. Eventually, she realizes that she fell in love with the hero, and hence their journey begins...

Taking place in 1930s Japan and China, Kasumi Kenshiro (the uncle of the lead from Hokuto no Ken) is forced to leave his teaching job and settle an old gang rivalry with the help of his martial arts. Along the way, he meets the son of one his triad buddies, an old flame, and a mysterious old man who teaches him new techniques which will assist him in his quest.

This is a collection of loosely interconnected stories where the main characters are all animals, especially the tiger who is the hero of the first book.

Our hero Vash the Stampede disappeared for two years after blasting a crater onto the moon above the desert planet he saved from annihilation. But with good people and bad alike trying to track him down, he won't stay lost for long! Count on more crazy gunslinger action, new dastardly villains...and a new outfit, to boot!

Note: Nightow changed publishers to Shonen Gahosha and the series continued to be serialized in Young King Ours magazine. Due to the original publisher retaining the name Trigun, Nightow had to change the title to Trigun Maximum, which isn´t a sequel but a new name for the rest of the series. The first 3 volumes were published under the title 'Trigun' and the entire series compiled into 14 books as 'Trigun Maximum' (the numbering was also restarted when the title changed).

Won the Seiun Award at the 48th Japan Science Fiction Conventionwere for the best comic of the year.

A miniseries prequel about the encounter between Rain and Zol. This is a prequel to Immortal Rain set before Machika's birth. Machika's grandfather Zol, who works as a bounty hunter by the name of Grim Reaper, encounters Rain, who turns out to be Methuselah, the most wanted man in the world. Why did fate bring these two men together and what is hidden behind Rain's clumsy and kind personality?

From Aku Tenshi:

The world of Waq Waq is a place where machines attack the black-blooded humans, whose only defense are the Sakimori, humans chosen to partner up with the Goujin-zou, a race of machines that grow stronger when melded to humans. Shio and his Sakimori father, Al, upon entering a village, are attacked by the machines. As Al falls in battle, he leaves his son to become the new Sakimori and guardian of a mysterious young girl, believed to be god, found at the heart of the battle. Waq Waq is the story of Shio as he battles to protect what was entrusted to him by his father. Let the battle for God begin!

From Storm in Heaven:

Beat has always dreamed of being the Golden Hero of Totia. He made a pact with his best friend Ricercare (Rice for short) to join forces to annihilate the demon king in order to achieve this aim. Yet a twist of fate causes him to abandon his goals and fight alongside Rice to protect the demons. Just how will they fare against the entire nation of Totia? And can Beat protect Rice from the hero of Totia before it's too late? Cute and heart-warming, this amusing five-volume series also includes interesting side stories rich with magic and beautiful art.

From Wingtip Cafe:
Rina is always busy studying and working to support herself. After the depressing news that she again lost first place in the school rankings to Julius, an expressionless guy who is her arch rival, Rina finds Milch, a little fairy girl. Later, she meets Sylvie, a Fairyland knight who has come to rescue Milch.

From Kokoro no Oasis:

Tomas is a proud and fearless assassin who has never failed a commission. So what happens when he's commissioned to kill Myra, an immortal vampire?

Bored of sitting around holding a wine glass all day, the Demon Lord is looking for something new. Something cute. Someone like Komomo, the level 0 heroine who has just appeared before him, ready to vanquish him like all heroes (or heroines) do. Faced with a demon king who'd rather watch TV under a kotatsu and make out with her than spread evil over the land, what will Komomo do?

* Also include are the following short stories:

• Calling in vol. 2
• Stray Doll in vol. 2

Rushuna is a blonde and very beautiful senshi (gun expert) that travels through the world with one purpose. This is to make the world a peaceful place by, instead of fighting with weapons, taking away people´s will to fight by giving them a smile. Although she doesn´t want to fight, she is forced to and shows amazing gun skills. In this journey she meets Yajiro, a mercenary swordsman, who joins her on her journey.

Walking home from school one day, Noriko is innocently caught up in a terrorist bombing. Rather than being blown to bits, she finds herself transported to another world; a world in which darkness seems on the rise, as its powers desperately search for a being known as the Awakening whom it is said will awaken the Sky Demon. She finds this new world to be dangerous and overwhelming, and Noriko has little choice but to throw her lot in with the mysteriously powerful man she encounters upon her arrival. The enigma of this world and her role in it will gradually unfold, but first things first: Noriko must learn their language!

In 2004, this manga won the 35th annual Seiun Award for best science fiction comic.

By day, Kusakabe Maron is an ordinary high-school girl with more than her share of problems. But by night, she is Kamikaze Kaito Jeanne, the reincarnation of Jeanne d'Arc, also known as Joan of Arc. Her mission: to hunt down demon-possessed paintings and exorcise the evil spirits! Too bad accomplishing this mission puts her into conflict with the authorities, who view her as a mysterious stranger vandalizing works of art. With only the help of angel-in-training Finn, she must survive high school during the day and battle evil by night!

A series of light novels ispired from the manga has also been published in 2013, written by Matsuda Shuka and illustrated by Arina Tanemura.

One day, suddenly... a night where the moon shines like never before, a boy meets the otherworldly Serin, a denizen of Chaos, only to die and become the undead. Now immortal, he can no longer exist with humans due to an ancient law... A tale of revelations that begins as he returns to Chaos, the start of a new adventure!