Well that's terifying to watched, especially this anime was design for education to children. I got goosbumps when from all 3 kitten, only one live and go on with happy music without acknowledge theiir 2 other brothers. That the most subtle horor i ever seen with their intention or not. As for the plot is really mix with one scene to another scene happens with little to none explanation. I get it's for nuclear warfare, but i dont think children gonna get the message without any explanation from teacher. Still is okay watch, Hey if you have time for less 30 min give it a go!