Excuse me while I shed a proud tear or two. If you're not swimming deep in the K-pop scene, as they bid their farewells, you might be forgiven for being (depressingly) unaware of SISTAR. No, on second thought, step up for your lashes, such ignorance is unforgivable.

I kid, but for years now, SISTAR has been arguably the most reliable force in Korean pop music: the Queens of summer. While other groups tend to jump around seasons, marketing a winter album or the like, SISTAR knew their power and stuck to the plan. Each and every year, as the water warmed and people headed to Busan's beaches, Hyolyn, Bora, Soyou, and Dasom and would be back with another summery earworm – and they never failed. It was always a hit, what's more, it always deserved to be, instantly catchy and effortlessly fun, as the best of Songs of Summer should be, in any country.

After 7 years of returning like clockwork, they had become something to rely on for Koreans and K-pop lovers worldwide, as certain as sunburn. As I swept through the last three summers living in Korea, their latest single was ubiquitous, as certain to be heard at a party as in a Baskin Robbins (the only ice cream store for Korea, apparently, thank you very much).

They were the rare girl group that truly felt complete. Sticking with four members rather than the often bloated garrison many labels opt for, each had a presence wholly her own. Hyolyn, their unflappable leader; the badass, seemingly permanently existing in a state of tan, tattooed and without a _____ to give. Bora, sporty and effortlessly cute, Soyou seeming moodier and keeping a mysterious distance, and Dasom, focused and intense, boasting a solid acting career all her own. What's more, they didn't just rely on one lady with real pipes to carry the actual singing, with Hyolyn commanding true power and Soyou with her softer grace, offering perfect foils for each other on any track.

All that said, their passing on means much more than simply being out of a guaranteed seasonal jam. In the past few years, the last generation of chart queens have been moving on, inevitably making way for the new. So, that battle begins: who will be next to rule our hearts (and charts)?

For those not already versed (or obsessed) with the K-pop world, the fickle nature of the scene cannot be emphasized enough. In no other scene is the "you're only as hot as your last song" more true. Eminem may still be getting by on the embers of his once vital career, releasing turd after turd: this would never fly here. Every group will have intense (I do mean intense) super fans, but unless a given artist is a listener's true favourite, their loyalty will swing at the drop of a hot (or limp) tune.

A prime example being T-ARA, who were the villains of the K-pop world for a time, marooned by bullying rumours and other nastiness. A Korean friend's teenage sister remarked at the time, with furious conviction, "I hate them. They're bad," not one week before 'Sugar Free' hit the market. Several days later I encountered her gleefully humming the tune, when asked how she could flip back so quickly, simply a shrug, a laugh, and a bemused grin. On the other side of the coin, AOA spent years as a relatively under-appreciated group, only gaining true, widespread popularity with the release of Like a Cat in 2014.

For a time, they seemed poised to run the scene, but as the industry suddenly caught on as to just how captivating member Seolhyun is, scoring endorsement after endorsement, young Koreans seemed to turn on them. Bare in mind, saturation through ads is the pinnacle all pop artists here seek to reach, so it's not from a rejection of artistic compromise, but something more arbitrary, a sort of jealousy that any single female seems to bare when she becomes too big (industry leader IU has borne the brunt of this for years). AOA released their first full Korean studio album after years of mini-albums (EPs) this year, and while it enjoyed the kind of success that's inevitable for a group so widely known, there seems to have persisted a sense that is wasn't as big as it should have been.

So, this is the landscape into which new contenders enter. Love to hate, hate to love, at the drop of hat. Hence, obviously, predicting the next big thing is more of a gamble than, say, crowning Ariana Grande early was several years ago. For the time being, the two clear leaders seem to be TWICE and Black Pink (stylized as BLΛƆKPIИK), with the former being the truly ubiquitous leaders.

Trust us, you can't fathom it. Everything in Korea is TWICE at the moment. Picking up Kendrick Lamar's DAMN. at my local music store, the owner and I ended up discussing current trends as we always do. He hadn't seen anything at TWICE's level in a long time, he said. "Boys always want to buy the latest girl groups, but I've never seen a fervour quite at this level. They really love the TWICE girls, each and every one of them.

What's more – and no small feat in Korea – young girls love them, too. Chatting K-pop with a classroom of grade school kids, mostly girls, I was instructed as to their truth. IU (my personal favourite, mind you) is "bad, a good singer, but a bad mind," but TWICE? Infallible, it seems.

They are, after all, running on a string of mega-hits, genuinely catchy and immediate tunes, including 'Cheer Up' and 'TT'. They've earned their glory, however potentially momentary it may be. Just remember the constant gusts of change: I've already had many of my students tell me they don't like the new single, 'Signal', the way they had their "other stuff". Uh oh. To my ears, it is indeed a weaker song, but delving into the full mini, I found that every other song on the release had more to offer. A baffling choice by JYP, a label error rather than the group's, to be sure, but will "the kids" look beyond the single?

In the lightspeed pace of K-pop, TWICE has plenty of time to recover, seeing as they'll almost certainly have another single or mini-album dropping by the end of the year, but it does open the playing field a bit more. Black Pink has a solid following, likeable members, and a mega-hit of their own in 'Whistle'. In a music scene in which fans love to choose their favourite member and obsess over them, Black Pink's smaller collective allows each respective lady more, shall we say, screen time, but also presents fewer options to choose from for a hyperactive audience. Naturally, SISTAR had 4 members and dominated summers, so I'm fully behind a Black Pink Nation. For the time being, though, this is TWICE's world to lose.

The battle will continue, but for now let's simply accept one stark truth: this is the last summer of your life with a new SISTAR jam to vibe with. Take it in. Appreciate it. Good luck, ladies.

You can find Chase tweeting over @Perlmanator.