Butterbelle

ButterBelle is the femslash ship between Buttercup and Princess Bluebelle from The Powerpuff Girls fandom.

Canon
In the episode "Once Upon a Townsville", Buttercup mistakes Bluebelle for a Zombie. Bluebelle, thinking that Buttercup is a prince, kisses her, before realizing that she is not a prince. Their relationship is not explored throughout the rest of the episode though.

She then introduces herself through song. She proceeds to make many attempts to get a prince to save her such as jumping into a volcano, taking a raft off a waterfall and trying to eat poisonous apples. Buttercup and her sisters end up saving her every time.

The two do not have any strong connections, apart from the kiss. However, it is known for being one of the few same-sex kisses in children's cartoons. The ship is controversial among some though since Buttercup is a child and Bluebelle is a fully grown woman.

Fanon
Due to the kiss between the two, despite the age gap between them, many people have shipped them together. The ship is relatively small. Some fanart has been made. As Bluebelle only appears in one episode, the ship is not extremely well known.