This is the season that stops pretending it's a story with songs in it and admits it's songs with a story attached. Every episode builds to a full CG performance, and you learn to sit through the lessons and the agency politics because you know the stage is coming. ST☆RISH are past their debut now, QUARTET NIGHT are breathing down their necks as senpai who actually outclass them, and HE★VENS shows up bigger and louder than before just to remind everyone that talent alone doesn't win. Haruka is the quiet engine underneath all of it, writing the songs that make these boys work, and the show keeps her exactly where the fandom wants her: the center that never picks. Shining Saotome still enters a room like a special effects budget with legs. You came for the music, you stayed because six idiots in coordinated outfits made you care about a composition deadline.

Picking up where the third season ended, the fight over who will open the Triple S international sporting event is still in turmoil after HE★VENS of Raging Entertainment crashed the contest between QUARTET NIGHT and ST☆RISH. An idea from QUARTET NIGHT sets all three groups toward a new stage, while HE★VENS vows payback against the other two. Meanwhile, the six members of ST☆RISH, fresh from their startling debut, move into the master course at Saotome Academy alongside Nanami Haruka, who is just starting out as a composer. They keep training seriously to become top idols and composers and sign with Shining Agency to work as entertainers. Before long, senior idols and odd foreign idols with peculiar habits cross their path, and everyone gets swept into a race for a puzzling Newcomer Award. The show is a musical idol comedy drama with a touch of romance.