The world is at peace, but there are still everyday dangers. So, a new breed of protectors, known simply as "Heroes" have arrived on Earth. Shy is Japan's new Hero, but is she ready to be a Hero? What does it MEAN to be a Hero anyway?
Shy returns to school only to find herself faced with Iko Koishikawa, a girl whose injuries she blames herself for. As if that wasn't stressful enough, a mysterious young boy sows discord and forces the girls to face the darkness in their hearts.
Koishikawa takes Momijiyama out on the town in an attempt to thank her for everything she's done for her. However, Momijiyama's introverted nature and shut-in lifestyle make this difficult. The two of them are then unexpectedly summoned by Unilord.
Shy faces off against Stardust for the right to remain a hero. To stand a chance, Shy has to discover what drives her as a hero and fuels the power of her Heart-shift bracelets. Heroes from the Black Cross help manage the aftermath.
As Shy searches for ways to strengthen the power of her heart, she finds support and inspiration in unlikely places. Help and begrudging assistance from Lady Black helps her understand struggle more as they help someone together.
Unilord sends Shy and Spirit on an urgent mission to the North Pole. There, they rendezvous with China's hero and work together to investigate the fate of researchers who had lost contact with the Arctic Base.
