Following their performance at the Black or White event, the idol group IDOLiSH7 is at the height of its popularity, with offers for various concerts and work coming in every day, much to the joy of the seven boys and their manager. However, as their fame continues to rise, Riku Nanase's health begins worsening due to the heavy workload. With the gigantic idol duo Re:vale showing interest in the group and the reopening event of the Zero Arena coming up, IDOLiSH7: Second Beat follows IDOLiSH7 as they not only struggle to adapt to the challenges of the idol life but also to face their personal troubles, all while continuously meeting the expectations of their treasured fans.

IDOLiSH7 is more successful than ever, but no one is smiling because a new threat has taken the stage: the debuting idol group ŹOOĻ. Managed by the nefarious entertainment executive Ryou Tsukumo, they will stop at nothing to get their way, resorting to all kinds of underhanded tactics to bring down their rivals. TRIGGER's image has already been ruined by scandal, and IDOLiSH7 and Re:vale are headed for the same fate—or worse. Meanwhile, Zero, the legendary idol who disappeared 15 years ago, continues to haunt the present through those he left behind. His manager seems to be in contact with Tsukumo for his own schemes, and Zero's songwriter reveals himself in a letter after having been missing for years. IDOLiSH7 finds an ally in Re:vale to thwart ŹOOĻ's plans while trying to make sense of Zero's colleagues' actions, but it may be impossible for everyone to emerge unscathed.

After the death of Saizou, Kabamaru's horribly strict grandfather and Iga ninja teacher (sensei), an old lady, Ran Ookubo, claims that she received a letter from him asking her to take care of his grandson. So Kabamaru runs off with Lady Ookubo to the big city Tokyo to gorge on yakisoba, ramen, chow mein, and attend a regular school—which turns out to have weird quirks of its own. (Source: ANN)

The VENUS Program is an idol scoring system that is entirely impartial, using AI and data to rank candidates based on an array of factors. To determine the rising stars of the idol industry, the annual VENUS Grand Prix is held utilizing these algorithms. Among all the idols that have participated, none have been as outstanding as Mana Nagase. However, on the day of the tournament's finals, a tragic accident suddenly ends her career. Kouhei Makino, who previously worked as Mana's manager, continues his career at Hoshimi Productions years after her death. Wanting to build a new team of idols, he accepts interviews from various girls. Unexpectedly, one of the interviewees is Kotono Nagase, Mana's younger sister, who is striving to carry on her sister's legacy under the tutelage of her former advisor. Also auditioning is Sakura Kawasaki, whose voice sounds astoundingly similar to that of Mana. Both Kotono and Sakura pass the evaluations, joining a group of eight other aspiring young girls. Living in a shared dormitory, the 10 members work together to learn more about what it means to harmonize as a team. United by an ambitious endeavor, the girls compete their way to the top as they traverse through the unforgiving world of idols.