Nodoka overhears her classmates taking about the recent monster attacks, but Rabirin implores her to keep her Pretty Cure identity a secret. Meanwhile, Nyatoran leaves Pegitan to look after Rate while he tries to find a partner, but Rate sneaks off leaving Pegitan to find her. However, another Byogen general, Shindoine, infects the water source in Chiyu's family Onsen at their inn. Nodoka transforms into Cure Grace in front of Chiyu and reveals her identity, but was overwhelmed by the MegaByogen. Chiyu asked Pegitan to lend her his powers to help Cure Grace as she can't last long in her fight. Her own resolve resonated with the penguin and allowed Chiyu to transform into Cure Fontaine. Together, they both defeated the MegaByogen and purify the Water Spirit trapped in it. Afterwards, Nodoka explains to Chiyu everything and entrusts her to look after Pegitan.