At its core, this manga is about despair, trauma, helplessness, suicide, and what makes life worth living for. Whether or not you will enjoy it depends on if you can relate to the characters and what they're experiencing. The main bulk of the manga is the characters dealing with their inner turmoil and learning to overcome it. It's a psychological drama through and through. It's philosophical, in a dark way.
That being said, it's not for everyone. It's a story about human suffering. The drama and horror comes from the emotions and life experiences the characters go through. Some people might view the characters are woobies because of how much they suffer and how they deal with it. If you've never been through these experiences yourself, you might not be able to sympathize or might think the characters are overreacting. Or you just simply might not enjoy seeing the main character crying and having emotional breakdwons. But if you've struggled with any of these things yourself, you might enjoy the way the author depicts them. It's depictions of depression, mental illness, rape and suicide are so raw, stark, and painful to see.
But what really sells this manga to me, is that it doesn't just do a wonderful and real job of depicting these themes, it leaves the reader with a message of hope and recovery.
