Mangas

さいたまチェーンソー少女 -  Saitama Chainsaw Girl
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.
よくわかる現代魔法 -  Properly Learned Modern Magic -  Yoku Wakaru Gendai Mahō -  Yoku Wakaru Gendai Mahou
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.