Kirakira Stars Idol Project Nagisa

"You're the idol you used to sing to on stage?"
After their first live performance, Nobuyuki and Ai have a fateful encounter with the top idol, Nagisa Yukihiro.
Six months later.
With Miwako's kindness, Nobuyuki and his friends attend a joint lesson with Uesugi Productions, a long-established entertainment production company.
While getting involved with Nagisa through joint lessons, it is decided that an idol festival - DivaFes - will be held, but...

"What are you going to do?　What do you want to do as an idol?"
"I want to join in--no, I want to try!"

DivaFes in a joint lesson, and Ai takes on the trial to take the next step as an idol.

From Steam