It seemed that it was a promising anime. Later on it showed to be a non-brainier and even boring. One of the main characters seemed schizophrenic having his personality changing all the time. The other was a joke.
I've watched several animes with poor stories and of low quality, but after watching this one (49 episodes), I felt that I've wasted my time on it. I only kept on watching because I hoped it would turn out better, but it did not. The last episode made me scream outloud "give back my 100 hours of my life!"
The killing part of this anime is the storyline. It kills you because it does not make sense at all. And believe me, it is really bad.