Kiki, also known as Pudding Fong in the original Japanese version, is a central character in the anime. She is the fourth member of the titular team to be discovered and is notably the youngest of the group. Her DNA has been merged with the Golden Lion Tamarin, an endangered species, which grants her superhuman agility and a spirited, playful nature that closely mirrors the traits of her animal counterpart. In fact, her personality is so well-matched with her monkey DNA that her fellow team members often remark on how perfectly it suits her.

In terms of personality, Kiki is the most hyperactive and energetic member of the team, overflowing with a childlike exuberance that can sometimes come across as immature to some of her more serious friends. She loves to perform acrobatics, play games, and have fun, which is also reflected in her job at the Cafe Mew Mew where her enthusiastic stunts often lead to broken dishes. However, this cheerful exterior belies a deeply responsible and caring nature. Kiki’s mother passed away when she was very young, and her father, a master of various fighting styles, is often absent while training in the mountains. Consequently, Kiki is the primary caregiver for her five younger siblings, managing the household finances and raising them largely on her own. She misses her mother dearly and tends to avoid the topic, but she treasures the memories of her and is fiercely protective of her family.

Kiki's role in the story is not only as a fighter but also as a source of levity and emotional depth. She often refers to the other Mew Mews as "onee-chan," signifying that she sees them as the older sisters she never had. This dynamic highlights her need for family and connection beyond her immediate siblings. Her most significant relationship outside the team is with Tart, an alien from the Cyniclons. In a turn of events that showcases her innocent and open-hearted nature, Kiki befriends Tart when he takes her hostage. She sees him as a friend despite their opposing sides, giving him the affectionate nickname "Taru-Taru" and offering him sweets. Their unique bond is a key part of her development, as she struggles with the idea of fighting a friend during the final battles. In the end, she shares a kiss with him, expressing her hope that their goodbye is not permanent.

Throughout the series, Kiki remains a steadfast and loyal friend, willing to do anything to help those she loves. Her development involves learning to balance her immense responsibilities at home with her duties as a superhero, all while maintaining her signature optimism. Notably, she can be blunt and speaks her mind without hesitation, but her intentions are always pure.

As a Mew Mew, Kiki's abilities are a direct result of her Golden Lion Tamarin DNA. She fights with a pair of rings, which in the English adaptation is translated to a Golden Tambourine. Her primary attack is the Ribbon Pudding Ring Inferno, an acrobatic-based move where she summons a tambourine and bell ring to create a melody that unleashes a blast of yellow energy, encasing her enemy in a force field shaped like pudding. When transformed, her appearance changes to reflect her animal DNA: her hair turns bright blonde or golden yellow, she grows a long monkey tail and monkey-like ears, and her hands become covered in fur. She wears a short yellow jumpsuit with yellow leg warmers, fitting her designated team color of yellow. Her Mew Mark, located on her forehead, is in the shape of two monkey tails.