Basically almost every Anime has a really vague ending on what happens to the characters. atau shall i just say they usually have lebih wow moments from the middle toward the end rather than the very end. :/
The ending plot was a little unadvanced and simple, but it was satisfactory. But the excution of the actual ending was total rubbish, and it stopped with many ideas and possibilities left and very much things left unsolved. The artwork looked like it was a total failure in the 3D effects. It should've deserved much better. It was a really good anime.