After the incident in the park, Nodoka took Rate home and convinces her parents to keep her for a while, to which they hesitantly agree. At another world, the Byogens were aware about the appearance of Cure Grace and how it will ruin their plans on infecting the world. The next day, Nodoka goes to her first day at school, and the animals come with her in the hope of finding partners for Pegitan and Nyatoran. Nodoka discovers she is in the same class as Chiyu Sawaizumi and Hinata Hiramitsu, two girls she met the previous day. After school, Rate sensed another MegaByogen attack as she calls out and draws Rabirin and Pegitan back to her (Rabirin had broken up her partnership with Nodoka earlier in the day and left with Pegitan trying to follow her). Hoping to make up for her lost time, Nodoka wants to help protect the world as a Pretty Cure. Rabirin realizes she was wrong about Nodoka and the two reconcile. Nodoka transforms into Cure Grace and defeats the MegaByogen, freeing the Tree Spirit trapped in the monster.

Nodoka calls Chiyu over to her house when it appears that Rate has become ill. As there doesn't appear to be a MegaByogen attack anywhere, Chiyu believes that they should take her to the local Veterinary Hospital run by Hinata's family. Meanwhile, Hinata was running late to her friend's outing to the mall when Nyatoran rushed to her to return her lipbalm. This causes her to affectionately thank the kitten until his sudden talking amuses her. Back at the Veterinary Hospital, Rate was treated by a vet there much to Nodoka's relief until Hinata came in and showed them Nyatoran, forcing Nodoka and Chiyu to drag her outside. Nodoka and Chiyu fear that Hinata was going to discover their secret, until Nyatoran played it cool and told her he's the world's first talking cat. As both learned that Hinata is indeed late to her friend's hangout to the mall, they all decided to go there. However, a third Byogen general, Guaiwaru, creates a MegaByogen to terrorize the area. As both Nodoka and Chiyu transform and prepare to attack, Hinata, having returned to the mall to find them, was ecstatic and amazed on what she is seeing. Nyatoran, impressed by Hinata's spirit, offers to be her partner and allows her to transform into Cure Sparkle. Cure Sparkle defeats the MegaByogen, purifying the Light spirit and healing Rate. Afterwards, Hinata apologizes to her friends for being late and both Nodoka and Chiyu followed her to make sure she never tells them their Pretty Cure identities.