Just noticed an article about Shiroten, the street in Osaka-Jo park where the band busked before they were "discovered."  It was published in December 2022 as an English-language column in Japan's biggest newspaper. HARU and RINA are quoted in the following passage:

Four-piece girl band Scandal, who performed a solo show at Osaka-jo Hall in 2013, had similar experiences. The band performed at Shiroten for about two years until their major debut in 2008. Vocalist Haruna, 34, said there were no people to listen to their songs when they first started performing at Shiroten in their late teens, so they made flyers advertising the group and handed them out.
“Thanks to experiences like that at Shiroten, we were able to develop the mental strength to never give up, no matter what,” Haruna said.
Drummer Rina, 31, offered advice to aspiring musicians, saying, “Believe in your sound and always play your music with energy.”

link to the whole article— 
https://japannews.yomiuri.co.jp/features/japan-focus/20221120-71708/

I was recently in Japan and stayed in a hotel in front of Osaka-Jo park. I quickly went to the Shiroten street and saw a group of guys dancing with almost no one seeing them  . I felt very happy to see where they used to perform and also seeing Osaka Jo hall was everything for me. So happy to see the success they reached!

Further down in the article, it says that fewer acts are showing up, preferring to post on social media instead. What a mistake! You only learn stagecraft by being on a stage.
Did you ever notice how when Scandal comes onstage, Rina walks to the far side of her drums before heading toward them? That keeps the members spaced out across the stage instead of creating a traffic jam over by Haruna. She didn't used to do that. She learned it. That's stagecraft.