How long will you stay in the game? The last thing Kei and Masaru remember was being struck dead by a subway train while saving the life of a drunken bum. What a waste! And yet somehow they’re still… alive? Or semi-alive? Maybe it’s reanimated… by some kind of alien orb with a nasty message… “Your lives are over. What you do with your new lives is up to me!” And what this orb called “Gantz” intends to do with their lives is make them play games of death, hunting all kinds of odd aliens, along with a bunch of other ordinary citizens who’ve recently met a tragic semi-end. The missions they embark upon are often dangerous. Many die-and die again. This dark and action-packed manga deals with the moral conflicts of violence, teenage sexual confusion and angst, and our fascination with death. Hang on to your gear and keep playing the game, whatever you do; Gantz is unrelenting. *Source: Dark Horse Comics*

The manga's story begins when a peasant named Hanbee asks a girl named O-haru for her hand in marriage, but O-haru confesses that she is already thinking of another man named Masakichi from a neighboring village. When Hanbee seeks out Masakichi, he finds that Masakichi possesses a sword and the skills to use it, despite being a peasant. (Source: Anime News Network)

She is popular and has a hunk for a boyfriend, but there is that boy in her class who always stares at her, but never talks to anybody. On the way home that boy loses his phone, she picks it up, but he runs away before she can return it. Inside she finds article on lucid dreaming, and this is where it all begins...

Suzuki Ichirou, a straight young man who becomes besotted with another guy, Satou Yuuki, convinced his bishounen love is a girl trapped in a boy's body. Interestingly, author Oku Hiroya is one of the characters in the story, the best friend of Satou. The first three volumes of this series collect Oku's early short stories, including prototype versions of both Hen series.

The year is 2028, location in New Koshigaya. A young boy, Isurugi Neru, lives in a poor family and is forced to quit school so that he can find his own way in life. Neru on the other hand, only thinks of one thing: to take revenge on Yagami, a classmate, who's especially gifted and has humiliated Neru numerous times.

Despite the title, Hen is NOT Hentai. It does have sex, strong language, yuri, and other elements that might make you think "Hentai". Chizuru Yoshida is not your typical high schooler and she's all too aware of it! She has a talent with getting what she wants from her male lovers and often comes across as cold and manipulative... In truth, despite her experiences with guys, she has never been in love. That's until the fateful arrival of newly-trasferred student, Azumi Yamada, at her school. It was love at first site for Chizuru--indeed an unexpected turn of events for the story's vixen! Not only was she in love but with all things another girl. Chizuru goes through a brief stage of anger and denial and tries to convince herself that she couldn't possibly be attracted to such a simple-looking, shy, and naive girl! To her despair she finds herself constantly thinking of Azumi, so she finally resolves to become friends with her, but it's not too long when she starts to push things along with Azumi... (Source: Manga Project)

Ichiro Inuyashiki is down on his luck. While only 58 years old, his geriatric looks often have him written off as a pathetic old man by the world around him and he's constantly ignored and disrespected by his family despite all that he's done to support them. On top of everything else, his doctor has revealed that he has cancer and it appears that he has little time left in this world. But just when it seems things couldn't get any worse, a blinding light in the night sky strikes the earth where Ichiro stands. He later wakes up to find himself unscathed, but he soon starts to notice that there's something…different about himself. (Source: Crunchyroll)

A special one shot that shows what Nishi does in his spare time.

The story of Nishi and Izumi, before the events of GANTZ.

Oku Hiroya tells in this manga what inspired him to draw GANTZ, and his love of Sci-Fi movies.

The main character is named Nagatomo, he is an astronaut and a scientist in charge of a secret operation about experimenting cryogenics on human subjects such a assasins or political prisoners, all inside a spaceship called "RETRO". Suddenly he wakes up inside the ship only to see outside a huge amount of black spheres floating in space, he first believes they could the debris of something, then he realizes there is life activity inside them and leaves the ship to bring one of those spheres inside, then he proceeds to open it and founds a girl inside it, Kishimoto. Suddenly, Kishimoto is transfered along Nagatomo to a GANTZ room that looks like it's the Tokyo one, the black sphere inside the room starts playing the radio song and reveals the target, the "comedian alien", then sends both to the battle area. Kishimoto is wearing her GANTZ suit now but Nagatomo is only wearing his space suit, they fight the aliens (Kishimoto proves to be useful, because she knew about the missions) and are sent back to the room. The "Astronaut" gets 6 points and "Big tits" gets 0, Kishimoto decides to stay in the GANTZ room because there is no place she can go back, Nagatomo leaves but not before saying he will be back. Source: mangahelpers

Hiroya Oku’s first completely new series in four years! The protagonists are... six middle-aged men?! The story is set in a share house inhabited by six men approaching their 60s. In this "utopia" filled with men who have seemingly given up on their current lives, an unimaginable development is about to unfold. (Source: Shogakukan, translated)