While in all official translations they're referred to as Cuties, they're called "Idols" (アイドル) in the Japanese version.
While their origin is listed as Sora, as this is where both Sora and Sham are from, the concept of Sora and Sham as idols originated from Acceleration of SUGURI 2, although they were not shown in idol outfits at this time. One of the earliest renditions of the idol design appeared on Hono's Twitter on Nov 21st, 2013. This design, along with an idol design for Sham, was later used in 200% Mixed Juice!, before being added to 100% Orange Juice! almost 5 years later.
According to CEO, Jakke Elonen, the original pitch for an idol song to accompany the Cuties came from the lead programmer Tony Blomqvist who meant it as a joke. Composer DEKU and the voice cast were enthusiastic about creating the song, resulting in the idol theme in the final cut of the DLC.
The idea of Sora and Sham putting on a live performance in 100% Orange Juice! was teased in an April Fools announcement shortly before Cuties was released.
Although the Cuties cannot choose Wins norma, they still have voice lines for picking Wins norma, contrast with Star Breaker who has no voice lines for choosing Star Norma.
This can be heard in-game during Bounty Hunt mode, where the Wins Norma voice lines are played when choosing the Fame norma.
Unlike Tomato & Mimyuu, Sora & Sham cannot equip accessories separately, except for hair colors. All other cosmetics and will be set for both characters as one unit.