Sakurazaka Hiroshi manga
The story revolves around Koyomi Morishita, a clumsy high school freshman girl who is often mistaken for a grade-schooler because of her shortness. Koyomi becomes a disciple of Misa Anehara, a 25-year-old graduate student who happens to be one of the most powerful modern-day magicians.
From Horobi no Michi: Kirisaki Fumio's just an ordinary highschool girl in love... ...but then she finds out that the guy she's fallen for happens to like someone else. And then she gets into a fight with a friend... that and various other things are getting her really down... ...so she decides to go out and get a chainsaw. And take it to school. And kill the boy she likes, and herself afterwards. Along with anyone who happens to get in the way.
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.