I concur with Orie - my comments here are in no way intended to disrespect the poster.
All the above said and done, Kenji Yamamoto's plagiarism is absolutely no different to the plagiarism of many Japanese composers; Masamichi Amano, Yoko Kanno, Naoki Sato, Toshihiko Sahashi, all spring instantly to mind as some of the worst offenders and there are probably a dozen more I've forgotten. The only difference is that Yamamoto got caught - or, more to the point, the popularity of the show outside of Japan made his plagiarism "more public" and Toei more-or-less had to disown him to save face.
Yamamoto's music is good. A dozen cues have plagiarism to one extent or another, and a handful of them are plagiarised almost note-for-note from existing cues.
Big deal.
Both main themes in Amano's famous Giant Robo series were direct plagiarisms from Western composers - theme A from Maurice Jarre's "Is Paris Burning?" (
https://www.youtube.com/watch?v=E5dxoIXj9LI) and Theme B from Bill Conti's "North And South" (
https://www.youtube.com/watch?v=ZL8oMlRBOtU) and the rest of the score is littered with thefts from sources as diverse as Jerry Goldsmith (Masada), David Arnold (Stargate), himself (various scores), Hans Zimmer (backdraft), and many more. Amano quoted previous scores all the time, and even completely recycled a cue originally written for a sex scene in a gay hentai movie (Boy's Legend) as the finale for Battle Royale II. Barely a Yoko Kanno cues exists which isn't influenced by, or outright plagiarised from, herself, another Japanese composer, a Hollywood composer, or classical composer - and frequently all at the same time.
I've learned to be comfortable with it. If I couldn't be comfortable with it, I would have to more-or-less abandon my interest in Japanese film, television, and game music.
Yamamoto pushed his luck a little too far and it ended his career... but he's not the only one, and he's not the worst offender. The only thing he did that was different is that he didn't make his plagiarism choices very well. He ripped off a popular American film score by a top-tier blockbuster composer from 2009, and recycled a whole cue, almost wholesale, just a year later in a TV anime that he KNEW would be scrutinised in the West and specifically in America. I mean, how bloody stupid can you get? If you're going to steal something, you don't parade it in front of the original owner less than a year later.