I don't have words to express the amount of emotions this anime truly have. This anime is a rollercoaster of emotions.
It shows how can a student 's life changes when he/she gets a mento who holds his/her life's string. Here Koro Sensei is more than that. He was more than a teacher that a student would ever imagine. The classroom, the students, the teacher, everything that this anime have is just wonderful.
At the end of the Anime everyone will just have one question, why can't they have a teacher like koro sensei in there life ? The last 2 episodes are just heart wrenching.
Highly recommended!