Ni Hao, Kai-Lan (simplified Chinese: 你好, 凯兰; traditional Chinese: 你好，凱蘭; pinyin: Nǐ hǎo, Kǎi Lán!; Hello, Kai-Lan) is an American-Canadian animated (anime-influenced^[1]) interactive children's television series that premiered on Nickelodeon in the United States on November 5, 2007. It also premiered on the Canadian television channels Treehouse TV and Télé-Québec.

Ni Hao, Kai-lan is based on the childhood memories of the show's creator Karen Chau growing up in a bicultural (Chinese-American) household. "Ni hao" means "Hello" in Mandarin, and Kai-Lan is the Chinese name Chau was given at birth, which was later anglicized to Karen. It was also based on the classic short series Downward Doghouse.

In the Season 1 finale, it is stated that they all live in California. Ni Hao, Kai-lan introduces its viewers to the Mandarin Chinese language, along with elements of Chinese culture and values, and intergenerational families (e.g., Kai-lan and her relationship with Ye Ye).

Episodes generally feature breaking the fourth wall, 11 minutes of interactivity,^[2] a target word that is repeated multiple times,^[3] a few words of Mandarin Chinese vocabulary, one or more of Kai-lan's friends having a negative emotional response to some action or activity (problem), Kai-lan thinking out loud (observation), cause-and-effect problem solving, and before saying goodbye (at the end of each episode), Kai-lan says, "You make my heart feel super happy!" Later installments added Kai-lan saying this phrase in Mandarin after she said it in English: "Ni rang wo hao kai xin!"

Kai-Lan is the host and main character, a playful and adventurous young girl with a big heart. She speaks both English and Mandarin Chinese, and she is eager to share her language, her culture, and her playtime with her animal friends and the viewers at home. Kai-Lan is a natural leader but she is also thoughtful and caring with a gift for helping her friends when they really need her. Her favorite animal is a dinosaur and in her music group, she plays her tambourine.

Kai-Lan is voiced by Jade Lianna Peters.

Ye-Ye (simplified Chinese: 爷爷; traditional Chinese: 爺爺; pinyin: yéye, "paternal grandfather") is Kai-lan's grandfather and legal guardian. He was born in Hong Kong and lovingly passes on his exciting traditions to his granddaughter. He provides Kai-lan with gentle guidance, leading her to find her own answers, at her own pace. (Kai-lan's parents and other grandparents are not known.) He can play the tuba. He also enjoys picking apples and making dumplings for Kai-lan and all her animal friends.

Ye-Ye is voiced by Clem Cheung and Ben Wang.

Rintoo is a rambunctious anthropomorphic yellow-and-black young tiger with a lisp who often acts before he thinks. He likes to play rough but when it comes to his friends, he is always willing to compromise. He is an avid fan of dragons and racing racecars. Even though he is with Hoho most of the time, his actual best friend is Tolee besides Kai-Lan. He plays the xylophone in Kai-Lan's music group.

Rintoo is voiced by Jack Samson.

Tolee is a gray koala who loves pandas and fruit (especially apples, bananas, and pineapples). He is intelligent and always thinks before he acts and sometimes worries too much, but he never lets that stop him from having a great time with his friends. Kai-Lan and her friends can always rely on him for good ideas. Tolee also has a stuffed panda he affectionately named Pandy, and Tolee loves Pandy so much he cannot imagine being without him. He is the vocalist in Kai-Lan's music group.

Tolee is voiced by Khamani Griffin.

Hoho the white monkey is the youngest of Kai-lan's friends, so when he participates in activities, he often goes first. He is full of energy and enjoys being the center of attention. Whenever he jumps a spring sound can be heard. He can often be found jumping on his friends' heads or playing his turntables as the DJ in Kai-Lan's music group. Aside from his turntables and his friends, Hoho likes bananas.

Hoho is voiced by Angie Wu.

Lulu is a pink rhinoceros. She has a red balloon tied around her horn that helps her fly in the sky. Lulu is very energetic and sweet. Lulu's home is a castle in the sky. She is best friends with Kai-Lan. Her instrument is the piano. Her favorite fruit is the lychee. Some of Lulu's favorite games include dancing, playing house, having tea parties, and wearing a fairy outfit.

Lulu is voiced by Beverly Duan.

At the start of almost every episode, Kai-Lan wakes up Mr. Sun so she can start her day. With the help of the viewer, Mr. Sun rises and showers down smiling sun fuzzies to Kai-Lan and she gets tickled by them. He also knows how to play the French horn, so Kai-Lan and the ladybugs (playing the pi-pa) join him as a little music group at the beginning of Tolee's Rhyme Time and later joins Kai-Lan and her friends in the music show.

In one corner of Kai-Lan's backyard is a teeming mini-metropolis of ants called Ant City. The ants serve very important roles in the community: they deliver mail, they build things, and they love to play with Kai-Lan and her friends. San San is their leader along with his two right-hand ants, Bubu and Fufu.

San San is voiced by Zachary Gordon, Bubu is voiced by Luke Manriquez, and Fufu is voiced by Kyla Rae Kowalewski.