Ann is a fictional cat character appearing in "Chi's Sweet Adventure," identified as the sister of the main character Chi and another cat named Terry. This familial relationship remains unknown to both Ann and Chi throughout their interactions, though they form a friendship and regularly spend time together. Ann shares a similar physical appearance to Chi but possesses lighter gray fur with distinct dark gray swirl-like patterns in the original manga, where her eyes appear slightly sharper. The anime adaptation portrays her with almond-shaped eyes, a white and light beige coat, and brown swirl patterns.

Ann demonstrates a gentle yet solid personality, often assuming a responsible older sister role among the kittens despite being the same age as Chi. She stops other kittens during mischievous behavior, reflecting her mature and protective nature. She visits the park alongside her mother, Marie, and brother, Terry, showing obedience and affection toward her mother.

Within the park's kitten group, Ann is a consistent playmate for Chi and Cocchi (also known as Come-Come). Their activities include playing together, exploring secret spots, and participating in shared adventures. Ann is part of the group that discovers a mysterious hole leading to the fantastical world of Fluffyland, embarking on adventures there. She also provides information about a sighting of Cocchi's long-lost brother, prompting Cocchi's journey.

In extended universe narratives, Ann appears in the "Rioluverse + Sagwaverse," where Chi eventually realizes their sisterly bond. Ann interacts with characters like Sheegwa and, in a non-canonical crossover narrative, joins the "Honorary Toa Alliance," acquiring tools and a mask. These elements originate from spin-off content outside the core anime series.