Your middle and ring finger held in the palm by your thumb, your pinky and index finger jutting out like Satan’s horns — do you remember the last time someone flashed the rock-on sign at you? Unironically? If we’re counting fiction, my answer is “The Emoji Movie,” which says everything you need to know about the gesture’s current cultural capital.

And yet, there it was at Kero Kero Bonito’s concert Sunday night at the Great American Music Hall, displayed proudly by frontwoman Sarah Bonito. Despite its tacky, dad-rock glory, it was greeted with screams and replicated by the sweat-soaked crowd. Headbanging ensued. Someone was lifted into the air and crowd-surfed.

You could imagine this kind of energy directed at ‘80s hardcore punk or Scandinavian black metal, but Kero Kero Bonito is an indie-pop band previously known for its melange of internet irony, kawaii culture and children’s music. But similarly to your sister who used to take styling tips from JoJo Siwa but now dresses like she fell into a vat of Vantablack — Kero Kero Bonito is growing up. Its latest music abandons the ironic (or was it ironic?) Nickelodeon pop of its first album in favor of ironic (or is it ironic?) reverb-laden, guitar-heavy shoegaze.

Two years ago, Kero Kero Bonito played DNA Lounge like it was “Barney Live!,” with silly props, sugary synths and singalong lyrics. Now, while the band still has the silly props (a cute stuffed croc made an appearance during the song “Pocket Crocodile”), the G-rated lyrics are murmured over distorted power chords and a backbeat. While the group used to play instruments such as the toy xylophone, everyone now has adult-sized Fenders.

That doesn’t mean Kero Kero Bonito has retreated to grown-up seriousness — its indie rock is wiped clean of the overwrought emoting of its genre. But neither does that mean it has tipped over into punk’s bitter ironies. Sarah Bonito bounces around onstage yelling, “Who’s ready to rock?” with sincerity.

Or perhaps affecting sincerity? Here’s the rub: Kero Kero Bonito is shrouded in layers of ambiguous irony. You can see what you want to see. Whatever you end up finding, the title of its latest album’s lead single will echo in your head: It’s “Only Acting.”

This ambiguity perhaps accounts for the most shocking change from the group’s last DNA Lounge show in SF to its latest — the audience. Kero Kero Bonito’s fans are a big tent, encompassing otakus, hipsters, indieheads, poptimists and more. But at the DNA Lounge concert last year, the audience was decidedly tumblrcore, with the genderfuck styling, clubby outfits and idiosyncratic, colorful hair. But under the rococo ceiling of the Great American Music Hall, there were many more backward baseball caps and pastel shorts. The crowd had a distinctly rowdy, bro-y energy — a circle pit spontaneously formed during the encore number, “Trampoline.”

There’s nothing wrong with bros, tech or otherwise, but they seemed to be getting something different out of the concert than what my queer self was getting. The reason why I, hiding behind a pillar in the intimate venue, was brought to tears by Kero Kero Bonito’s music is because it wholeheartedly embraces femininity and inauthenticity — two affects that are stereotypically associated with queer men.

Sarah Bonito’s high voice is without the snarl of her punk predecessors, and her performance of cuteness and childishness is an unironic island in a sea of nudge-winks. Kero Kero Bonito’s music celebrates high femmedom while making clear by the contrived nature of its whole J-pop-meets-shoegaze sound that femininity is not a biological imperative but a performance.

But that still leaves the question of the moshing bros. What do they get out of this pat equation? Performing masculine rock culture — headbanging, moshing, rock-on signs — to such cartoonishly unmanly music is a funny sight, and that queerness, if you will, is exactly what the Sperry crowd is experimenting with. The crowd wants to push aside, for a while, the burden of embodying masculinity by calling attention to its own arbitrariness.

But the liberatory potential of Kero Kero Bonito has room for more than frat boys and queer folk. In its shifting ambiguity, it can accommodate anybody. Experiencing Kero Kero Bonito is like mainlining a drug cocktail of 4chan, Tumblr and cherry-emoji Twitter. And much like the endless sub-sub-subcultures that proliferate on those platforms, there’s a Kero Kero Bonito for everyone — you just have to look for it.