Kuki Sanban, known by her codename Numbuh Three, is a fictional character and a Kids Next Door operative. Numbuh Three has an extremely short attention span except when she is enjoying the things she loves. She is Japanese, but it is not known whether she was born in Japan or is simply of Japanese descent. She has a sister, Mushi.

Numbuh Three usually wears an oversized green sweater and sneakers. She is obsessed with flowers, cute things, and plush toys, especially Rainbow Monkeys. Her love of Rainbow Monkeys is so great that she can smell them over long distances.

Numbuh Three is voiced by Lauren Tom.