The orginazation is really good,I pretty like a anime which has clearly plot.It started in the small cave under ground.Then,They discovered level by level,experienced a lot of things.Let me reflected that the probability is exist,we must believe in ourselves.Who the hell do you think I am ? I think I've be confident and ideal after I watched.
Lastly,I hope that everyone should watch this masterpiece,It's worthwhile.I am still non-stop playing the opening song right now. XD
