I admit that I thought it is a teen series at first. Then I thought about watching it because many people were talking about it in a good way.
As people say, it was great! The topic, acting, setup etc. everything. There is nothing to say. I completed it in a few days.
It makes the characters question themselves. You can never see a character in any series that asks questions like "Where did I do wrong?".
A person's death is not just a person's death. It can be the death of many other people. And that series show it well.
High schools are terrible. You change after going college. You become like more human. Because in high schools we think like the world is turning around us. But when we go to college we realize that we are just "nothing".
What we do in high school is just cruel.
That series start with the death of a girl. And she says "These 13 people are responsible of my death". And she leaves a tape to them. The story starts here.
I don't want to give any spoiler. Enjoy it!