River

River is a mascot in Harmony Crystal! Go Pretty Cure!!. He can turn into a Cure Cell to assist Celyn Pierce's transformation into Cure Flight. In the Japanese version, he is known as Yoichi (洋一 Yōichi).

Appearance
As a pixie, he has a round aqua face and an oval-shaped body, His ears, limbs, and his small tail are teal. As a Cure Cell, he is inside the screen of the phone, and the phone is colored teal with a pink PreCure Charm Slot.

Before Harmony Crystal! Go Pretty Cure!!
River, along with Shadow and Pearl, was sent by the Queen of Harmony to find his Pretty Cure partner to defend the Land of Harmony from the Storm King.

The Arrival of Cure Tempest
River is mentioned by Shadow in The Arrival of Cure Tempest, stating that he was sent by the Queen of Harmony to find his Pretty Cure partner.

The Second Cure is Cure Flight!
River helps Celyn Pierce transform into Cure Flight to defeat Guber.

Last Cure, Cure Nova!
River and Shadow speculate about the dark energy coming from Celyn Pierce's sub. When the sub transforms into Guber, River helps Celyn transform into Cure Nova.