Ihara Shiro manga
On August 10 of 2019, humanity received a signal, which was verified for its integrity by hundreds of scientists, from an alien life form containing one message: let us meet on Mars on July 7, 2035. Thus began the creation of a space agency representing Earth as a whole named ST&RS. From there, things progressed quickly with man re-landing on the moon in 2022 and constructing many space stations orbiting Earth and the moon. The Space Academy was created to train the upcoming generation of ST&RS. The same August 10th that Earth received the message, Shirafune Maho spoke his first words and it was “Mars.” Since then, Maho has been an astronomy freak who has nothing but the universe on his mind. He decides he is going to apply for the Space Academy along with his childhood friend, Hoshihara Meguru, and recent transfer and super smart classmate, Amachi Wataru. The trio begins their almost impossible journey of being accepted into the school where only 1% of the applicants are allowed into the academy.
From MangaHelpers: The world is in a war against an alien race called "Mimics," who have taken over most of the world with a mission to eliminate the human race. Keiji Kiriya is a new recruit in the United Defense Force, which is battling against these "Mimics." On his first day of deployment, Keiji and his unit encounter "Mimics" and are all killed... Or was it all a dream? For some inexplicable reason, after every time he dies, he is resurrected and returned back to the day before the battle. Why does this happen to Keiji and how can he escape from this never ending cycle? Note: Based off the novel published in 2004, which inspired the Hollywood movie Edge of Tomorrow. Nominated for the Eisner award for the "Best U.S. Edition of International Material - Asia" in 2015.