This is a pretty good 1 shot manga that covers a bit of how Nine came to be in the Heroes Rising movie. Nine's character motivations in this are a bit dumb, but they can simply be chalked up to his delusions of grandeur that he's had (presumably) since childhood. Everyone is in character, and the 1 shot accomplishes establishing a bit of background info for all of Nine's teammates, despite being only a few pages long. Overall this manga is a nice read, but if you haven't watched the movie then there's really no reason to watch it, as it has no supplementary materialaside from specifically Nine and his team.