There is a critical mass of humor that a show must achieve to succeed as pure comedy. Where critical mass lies is of course a subjective thing—senses of humor being what they are—but as a rule it must be pretty high, because so few series ever seem to reach it. Too many comedies end up as perhaps-pleasant diversions, or worse, as hyperactive headaches (or even worse, as bottom-feeding feasts of vulgarity). Perhaps that's why so many comedies seek out alternate forms of support: romance, action, social commentary, emotional depth, depth of character. If you think of it that way, it's the truly brave comedies that head out into the world armed with nothing but gags and—they hope—guffaws. So when they fail to hit critical mass and flop around in forgettable comedic conniptions, be kind. Such series aren't the lazy couch surfers of the entertainment world, cruising by without putting in the effort to be intellectually or emotionally stimulating; they're the fallen warriors of comedy: valiant souls who died charging the enemy with a banana peel in one hand and a whoopee cushion in the other.

Okay, given all of the awful, lazy trash that gets pushed on us with a shrug and a “hey, it's just comedy,” that's a positively Pollyannaish view of comedic failure. But when you watch something like Muromi-san it can feel kind of true. Muromi-san isn't a very good comedy by any stretch. It's silly and pointless and not nearly funny enough to excuse either. But its heart is in the right place. It just wants us to laugh, and it tries plenty hard to make it happen; without falling back on gross-out gags or winking self-awareness; without relying on cheap “emotional” turns or will-they-won't-they triangles or even a whole lot of fan-service. It attacks straight on, gathering a mess of goofy mermaid-based vignettes, clumping them into fifteen minute bursts of comic energy and shooting them at us in hopes that we'll have a grand old time yukking it up about mermaid-fish kinship or 200-million-year-old grudges. It sticks to its guns and dies with honor. You want to respect it for that.

And it can be good fun in the moment. The series runs full-tilt at all times, rocketing from gag to gag, cutting away any extraneous plot or character-building to cram itself to maximum density with jokes. It rarely works any one joke long enough to wear it out and thus manages to cover a wide variety of gags. It gets a lot of mileage from the very unmermaidish personalities of its mermaids, especially overenthusiastic, ill-tempered, perverted, violent, cynical, and generally just weird and unladylike Muromi. It takes great pleasure in perverting legends (its version of the sinking of Atlantis is a highlight, as is its vision of the grubby capitalist reality of Otohime's undersea paradise). It loves violent physical humor (there's a running gag about vicious dolphin abuse) and has a great time devising personalities for various forms of aquatic life (which somehow only makes the dolphin abuse funnier). It gleefully and repeatedly punctures mermaid mythology (the ways in which mermaids show their fishy heritage are among the show's few forays into outright hilarity) and isn't above trotting out straight-up character-based weirdness (Levia-san, Muromi's Atlantis-destroying mermaid buddy, bathes in lava). It even dabbles in evolutionary biology humor. Its humor can be dark—slavery jokes anyone?—and occasionally a little nasty (a recurring joke about Muromi's abuse of one mermaid's ample breasts is in very poor taste), but the series' sincere desire to entertain always shines through.

In maintaining Muromi-san's runaway comic energy, director Tatsuya Yoshihara makes some artistic sacrifices. Like realistic backgrounds. The series' settings tend to be roughly drawn and short on detail. They're meant to look stylishly cartoonish, and they do, but they also look cheap. Characters, on the other hand, are well-drawn, as well as adorable and instantly recognizable thanks to their round-cheeked, pear-shaped faces. Yoshihara plays their cute exteriors off of their crude or selfish inner workings to solid comic effect. When not doing that, he's busy keeping the series' energy-o-meter pegged somewhere in the “toddler on crack” range. Muromi is a primary-colored riot of a show, every frame so packed with cavorting mermaids and other comedic action that there's no time to really notice the quality (or lack thereof) of Tatsunoko Production's animation. It's a good strategy for a show that obviously hasn't the budget of, say, Yondemasu yo, Azazel-san (which it compares itself to at one point). Despite the hyper tone, Yoshihara doesn't let Osamu Tezuka's score get overactive, applying its generally simple themes with commendable restraint.

When the series does slow down, Yoshihara displays a surprising aptitude for sweetly melancholic emotion—particularly during the episode in which Yeti and Harpy, the show's two most adorably odd takes on classic monsters, get in a mildly heartbreaking spat. That bit alone is enough to make one wonder if the show would have died had Yoshihara been allowed to nurture an emotional underbelly.

But the fact remains that it does die. Not a messy, splatterific death a la Demon King Daimao or even a progressive self-destruction a la Fractale; more an almost unnoticeable slide into senescence. Indeed it doesn't die while it's running. Its death comes when it wraps without any one joke peaking high enough to be remembered afterwards; when it fades quietly from memory, pushed into that compost heap where specific series decay into that undifferentiated mass we think of as “decent anime.” For all its heedless energy and machine-gun spraying of gags, the series can't wind us up enough to make a permanent impression; it can't muster enough comic invention to carve out a lasting place in our ever more crowded minds. Put simply, it fails to reach critical mass. And suffers the inevitable consequence.