This anime is amazing!!!
The animation, voice acting, plot, humor, music, and really every aspect of this anime is absolutely amazing!! I would definitely recommend giving it a watch.
I saw someone give this anime 2 stars because they disliked the ending. With an anime as powerful and eventful as this one, I can understand the director/author's issue with finding an appropriate up-to-par ending. The ending was very bittersweet and did leave a bit of a cliffhanger, but it's not THAT bad to deduct more than a star.
I would say that my own mini-issue with this anime is the romance aspect of it. The main character's first love being her favorite character is realistically weird. Despite this, its irony is funny and sweet.
In summary, this anime is awesome! Definitely give it a watch! It is a masterpiece!