I've recently been watching and finished season 1 of Attack on Titan, the most amazing anime I have seen in years, it's the first anime I actually want to see until the end. so Attack on Titan is about 3 friends, Eren, Armin and mikasa, who's town is attacked by dangerous beings known as titans, Erens mother is killed and Eren and the other 2 escape, Eren swore revenge on all titans, so after moving town, they join a military training camp, after 3 years they graduate and join the survey corps after a series of battles shortly after their graduation that nearly costs them their life. It's an amazing anime, you really should check it out
