So I was watching Youtube some time ago and stumbled upon on a anime video about some teens going to school (somewhat slice of life?), and they were suddenly attacked by aliens. All of a sudden one of the students were able to transform (not Heroman), and I think it was a movie but I have a hard time remembering. I looked it up but couldnt find anything on this thought. Its annoying that I can't find it... I know it is out there somewhere. by the way I believe the youtube title was in japanese.