The idea of a boy becoming independent from his parents and realizing he's not a baby unlike his sister is really good, but this was not made well.
Throughout the movie, main character Kun, was neglected by his parents and was just thrown in the scenes and situations, without him actually doing anything. The development he made wasn't very satisfying 'cause it seemed expected. Towards the end, he thought parents don't love him so he ran away and got lost. He was put through horror, and for what? That train of horror is a warning that he could send him and his sister Mirai,as he's having a big impact on her, in a bad place if he don't change his ''bad'' behavior. Instead of his parents teaching him it's bad to hurt people, to not throw a tantrum if thing don't go his way and to at least explain anything to him, he got mistreated, judged and scared as a reasonable resolution for his biggest flaw, not understanding the world around him. As for the rest of the anime, scenes are fantastic and super expressive but its like they just don't mach with each other or fit 'cause of these ''little flaws'' that just keep on adding up. Animation should help execute the story, but in this case i was just a little disappointed. Way too good quality 3D animation is made for an average story so it just couldn't compliment the already not well written scenes. This could've been a good anime but it really is a breathtaking animation with the average story. But still after this not so pleasant experience, i expect a lot of good work in the future. Music is good too :)