In the early 2010's I was starting high school, and it was around this time that I first started dabbling in makeup. The style I got hooked on originally was the korean "ulzzang" makeup style. I loved that it had a cute, natural look but also an unique eye makeup. I think it was while searching for tutorials for this that I stumbled upon gyaru makeup and fell in love with how dramatic the eye makeup looked, similar to the ulzzang look but even more detailed.
At this time the japanese gyaru community was on the decline. With the creation of the tsuyome substyle the subculture got some new life but shortly after it was starting to walk on it's last legs. Magazines documenting gal life shut down and traditional gal brands changed their style in favor of simpler fashion. It looked like japanese girls wanted to go for more natural styles.
On the other hand, at this time, the gaijin gyaru community was blooming. Many gals had made their own revivals of different substyles that had since long been out of date in Japan. This was when I rediscovered the ganguros (now called old school gyaru). As much as I liked the extravagant and beautiful makeup of tsuyome, agejo and hime gals, I did feel like it would be hard for me to maintain in the long run, so when I saw there were gals with simpler makeup, that also sported brightly coloured clothes, I was all for it.
Why I say rediscovered is because I had seen those kind of gals long before that, actually back when I first discovered japanese pop culture. In a manga magazine I read back in 2005, there was an article about gals talking about the style as well as some medias featuring gals! So it was a throwback to this time.
Anyways, this old style was the one that stood out to me the most among all substyles, I admit I have a bias for things from the 90's, but yes this was a style I could see myself wearing to some extent, and that I did, for a while...
Fast forward to the 2020's, after not seeing much from the gyaru community for a couple of years, it boomed, and it boomed big. Suddenly it seemed almost mainstream (at least compared to earlier), and not only the most recent substyles, but just about any substyle that had ever existed. It was like with the gaijin gals in the 2010's, everyone was taking up the old substyles and making their own mixes of substyles, even the japanese gals were going retro and wearing 15 year old clothing! And that's basically where we are today. I'm intrigued to see what the future will hold, and what's going to happen in another 10 years. Will there be new distinct substyles created? Will the subculture die off again or will it remain the same? Who knows?
Source: My own experience and observations from the last 20ish years. Please take everything with a grain of salt :3
(also i'm sorry if there are any grammatical errors, my english is not the best...)