Comment by Ekaros
Actually Japanese titles are explained by the reality that market is so crowded that no one reads the synopsis(backside) or even blurbs anymore. So putting it all in the title is best way to get enough information out to catch some attention.
Additionally, although this is potentially hearsay (IANAJCL), from my understanding Japanese copyright law is strict and names cannot be re-used, so to get around this they tack on a single sentence synopsis, so it’s incredibly difficult to run out of names.