Welcome to Streamers on the Rise, where we find streamers who are growing their channels, content, and audiences in extraordinary ways. Each week we’ll talk with a creator about what goes into livestreaming–both on and off camera.

PolarCub was 13 when she first came across Roblox.

Like much of Gen Z, a lot of her entertainment growing up was the internet, and she was browsing around one day, flicking through online dress-up games, when Roblox appeared. She asked her dad to make an account for her, loaded into the digital world, and started exploring. Because she was so young, she wasn’t able to use text chat–just premade phrases she could click to communicate to other players. That didn’t bother her; most other people she met were around the same age, and they used premade texts, too.

“I have very fond memories of just playing with other...