I've looked at my anime list, but out of the 200 anime I've watched, this is the first time I've given a rating of 1. Maybe you could say that the eps are divided into 3 episodes, 1-3 are good, 4-6 are not so good, 7-9 are bad, 10-12 are very bad, especially in the last episode where the storyline is "very forced".
