Taking place after the events that occurred in Hayate no Gotoku! Can't Take My Eyes off You. Hayate, Nagi and Maria return to their daily lives at the Sanzenin Mansion and the Violet Mansion. (Source: Hayate no Gotoku! Wikia)

Akane Motomiya and her friends Tenma and Shimon are pulled by a demon into another world, where Akane becomes the Priestess of the Dragon God. The people of this world tell her that she is the only one who can stop the demons from taking over; meanwhile, the demons want to use her power for their own ends. Luckily, Akane has the Hachiyou, eight men with powers of their own who are sworn to protect the Dragon Priestess.

Thought your life was bad? Sometimes, death is worse. There is no salvation, peace, nor god waiting to receive you into their care. But wait, a god? Maybe you are talking about that big black ball stuck in the room with you. Now you are thrown into a game, fighting green aliens and robot monsters for the chance to survive. When Kei Kurono is killed, he thus finds himself caught in such a game—a test of his skills, morals, and will to survive. His life is not his own; his death is spat and trampled upon over and over again. What happens if he does not listen? God knows. A word of warning: Gantz is not for the faint-hearted, but neither is it as simple as it looks. Gore, rape, and violence is rampant, as are portrayals of greed, violence, and all the ugliness that one sees in society today. [Written by MAL Rewrite]

The world is about to be turned upside down for Hajime Murata. First, a strange alien ship appears over Tokyo, and then a mysterious new transfer student arrives at his school wearing an ancient school uniform. His name is Muryou, and with his arrival, everything begins to change. Students suddenly begin to display amazing psychic powers, a giant white guardian keeps appearing in the skies over the city to fight off gigantic alien creatures, and men with threatening weapons are haunting the shadows of the school grounds. With all these strange events taking place around him, Hajime is determined to figure out the truth about a world he thought he already knew. This is his story: a tale of aliens and humans, starships and spies, and friends who are often more than they appear. Join Hajime as he uncovers the mystery of Shingu: Secret of the Stellar Wars! (Source: RightStuf)