Just read the novel. It's less than 200 pages and is superior.The only thing is that you may feel disappointed by Furuya.
Very bad adaptation that I wouldn't have finished if it weren't for the mangaka. I read it after reading the novel. To my surprise, it was worst than I ever expected. Worst characters, development, writing. Things just happen, without any sense of cause and effect, unlike the original. All the changes the mangaka made were for the worst. As the characters, and the manga as a whole, are written more like a juvenile cringe shounen manga.
The ending was good, not as good as the original, but closed some distance between the protagonist and the readers.