It first appeared in the last episode "The Home Coming" where Princess Ava use her powers to transform the Friendship Heart and the Magic Fountain because of Kate's pure heart as she says. Ava gave the Friendship Heart to Kate for her to keep forever and she says that the Ocean of Friendship will allow her to still continue to do Friendship Ceremonies and fulfill her duties as princess. It looks quite similar to the Friendship Heart but it's sky blue.