Alright so first of all, this is not really an "after series" thing but rather, a first impression based from the trailer I've seen (I'm sure you've read the title) so I'm not really gonna call on spoilers. I mean, I might mention stuff like their sub-unit name অথবা official story অথবা something but again, this already came from the trailer and some stuff they already released early. So basically we're all in this together. If আপনি have not watched the trailer then do so over here:
link অথবা if that link doesn't work then it should be in আপনি Tube at "Bandai Channel"
So, with that out of the way let's...
