[2] The first full episode was initially set to premiere on October 22, 2007[3][4] on Nickelodeon's Nick Jr. block in the United States, but was delayed to February 7, 2008, coinciding with Chinese New Year.

[5] "Ni hao" (你好 nǐ hǎo) means "Hello" in Mandarin, and Kai-Lan (凯兰 Kǎilán) is the Chinese name Chau was given at birth, which was later anglicized to Karen.

The series follows the adventures of Kai-Lan, a 6-year-old Chinese-American girl; and her group of talking anthropomorphic animal companions, Rintoo, a yellow 6-year-old Bengal tiger; Tolee, a gray 5-year-old koala; Lulu, a light pink 5-year-old rhinoceros; and Hoho, a white 3-year-old monkey.

Each episode is based around a series of events during Kai-Lan's day, along with obstacles that she and her friends are forced to overcome (with "assistance" from the viewing audience) relating to riddles, playing games, and working together.

At the end of all episodes, Kai-Lan thanks the viewer for helping her and adds, "You're a really great friend", saying again in Chinese in season 2 before "You make my heart feel super happy" before saying goodbye in 2009-10.