I loved Show by Rock in 2015. It was one of my favourites of the year, as was its 2016 sequel season. This third season, though, doesn't recapture the magic. I don't hate it, but I don't see the point in it either.
The show's set in Midi City, in a world that's all about rock bands. (It's based on a mobile phone rhythm game with at least twenty bands, although I don't know how many are playable.) Furthermore, everyone's an animal person. You can either be (a) cute and tiny, barely even knee-high, (b) human-sized and with your animal characteristics more understated, or (c) a tiny, manic CGI cartoon when you're performing on-stage.
Seasons 1-2 were about a four-girl band (Plasmagica), plus hot-blooded idiot comedy from a four-boy band (Shingancrimsonz). I loved them all.
Season 3 is about a four-girl band (Mashumairesh!!), plus hot-blooded idiot comedy from a four-boy band (Dokonjofinger). They're okay.
Dokonjofinger are actually quite funny and have a reasonably disinctive concept. They're rubbish and dysfunctional, only playing in a band together because their school's headmaster said it was either that or be expelled. Yasu has a mother complex, Hacchin loves fighting and bragging about himself, Joe is sickly and vomits blood all the time and Sojun is proud to be scum. In principle, that's entertaining. This franchise is great at hot-blooded idiot boy band comedy... but this new lot become less amusing when they calm down. In practice, I found them less consistently funny than Shingancrimsonz, who guest-star in a couple of crossover episodes.
Mashumairesh!!, though, are bland. Howan is the lovable Cyan-a-like protagonist, albeit in many ways created to be her opposite. (Cyan was a human who'd been transported to Midi City against her will, whereas Howan is a country bumpkin fox girl from this world who's always wanted to go to the city. Cyan was shy but talented, while Howan is outgoing but inexperienced. Also, importantly, Cyan was intelligent, while Howan doesn't have much between her ears and almost never says anything but platitudes when asked a question. I was amused by her wide-eyed wonder at big city life, though.)
Ruhuyu is the energetic one, which in practice makes her slightly annoying, with her "lunatic" catchphrases and (thankfully soon dropped) insistence that something must be a "case". Delmin is stoic and emotionless (i.e. fairly dull). The only one who's actually worth watching is Himeko, the standoffish tsundere who doesn't want to be in a band and by default says "no" to everything. She's neither lovable or fun, but at least her characterisation has layers. She's obviously in love with Howan, for instance, which is as heavily underlined as Plasmagica's Retroree's feelings were for Cyan.
Mashumairesh!!'s two chilly girls have compensatingly wacky hair, though. (Marshmallows!)
The killer, though, is that this new season doesn't have a plot. Seasons 1-2 had a "save the world" storyline and battles against evil monsters. Season 3 is just a slice-of-life series. Nothing much happens. The season finale generates its "drama" from avoidable idiocy. (Our heroines overslept on the day of their career-changing concert. Howan left her guitar at the studio, etc.) It can also be corny or eye-rolling, e.g. the non-murder non-mystery in ep.2, or "that's why 100% isn't enough for our friendship meter!" in ep.11.
I don't think much of Touno Hikaru's vocal performance as Howan. Howan's granny got tiresome. I mildly dislike the toned-down CGI, which feels more timid. I see this season has a different writer (Daisuke Tazawa) and director (Seung Hui Son) from the first two seasons, so I now have two names to avoid.
There's a Season 4 in 2021 with all the bands so far. I watched it, but with lowered expectations. There are fans who enjoy Season 3, I think because they like slice-of-life shows and because it has new bands? Personally, though, I'd call this season basically worthless. Dokonjofinger can be funny, e.g. ep.3, ep.7 and the end of ep.2. Even Mashumairesh!! have their moments, e.g. the funny reaction to the notebook in ep.4. Fundamentally, though, the lack of drama means that we're just watching random blobs of nothing. When it's good, that's effectively just moments of watchability in a void. When it's not, the show's a void.