Urutoraman Kosumosu: The First Contact

Yeah, you've read it right. This prequel had clearly no reason outside catching the interest of the Ultraman fans by presenting them the iconic villain from back the first Ultraman, because outside that purpose it serves absolutely nothing since there was no particular need to elaborate on how Ultraman Cosmos and Musashi met in the first place and, most importantly of all, this movie doesn't attempt in the slightest to show the reason why, in contrast to other Ultramen, both Ultraman Cosmos and his human host prefer to help monsters instead of just killing them. So, there's no point in watching this movie outside the fanservice thing and few, scarce laughs inbetween. It's watchable once but you're probably going to forget it, so I wouldn't bother in the first place.