Kai-Lan is a six-year-old playful, adventurous preschooler with a big heart. She speaks both English and Mandarin Chinese, and she is eager to share her language, her culture, 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. In the (aptly-titled) episode Kai-Lan's Big Surprise, she tries to put together a big surprise party for Ye-Ye, but all the decorations, the pineapple cake, and even her card fall victim to gusty winds.
Ye Ye (Mandarin word for 'paternal grandfather') is Kai Lan's playful, thoughtful, caring, paternal grandfather. He was born in China 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. He's known to pop out of places unexpectedly, but the gang just gets used to it after awhile.
Rintoo is a smart, competitive, impulsive and conceited five-year-old tiger and one of Kai-lan's best friends who loves dragons and racing race cars. He even shares a special roaring handshake (only in the introduction video and in earlier episodes) with Kai-lan: 'tiger-tiger roar!' He has a thirst for adventure and thrills and often pounces headlong into the action without giving it much thought. In Kai-lan's music group, he is the xylophonest. He is especially close to Tolee and Hoho, but in Sports Day, he hurts their feelings by bragging, in Playtime At Tolee's Tolee hurts Rintoo's feelings when he would not forgive him for accidentally ripping his painting, and in Kai-lan's Playhouse Hoho is seen hitting him in the knee. This is not the first time Rintoo has been hurt in some way. In Ni Hao, Halloween, Rintoo is excited to go trick-or-treating, but he sprains his ankle and has to stay in Kai-Lan's bed for the rest of the night. His catchpharse is 'I love (subject i.e. snacktime etc.)'.
Tolee is a five-year-old koala that 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 can't imagine being without him. The unimaginable, however, happens in Pandy's Puddle when he accidentally drops Pandy into a mud-filled puddle, the reason being he was trying to pull up a very large Chinese Turnip. He is the vocalist in Kai-lan's music group. His love for pandas culminated in the two part episode 'Kai-Lan's Great Trip to China' when the group traveled to China to meet a whole family of Pandas' including baby Xiao Xi Gua (Little Watermelon).
At age 3, Hoho the white monkey is the youngest of Kai-lan's friends, so when he participates in activities, he often goes first. He's full of boundless energy and nothing makes him happier than 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 resident DJ in Kai-Lan's music group. Aside from his turntables and his friends, Hoho's favorite thing happens to be bananas. In The Ladybug Festival, he wears an army T-shirt.
Lulu is a happy, enthusiastic pink rhino. Lulu is the same age as Kailan, six years old. She has been best friends with Kai-lan the longest. They have celebrated every birthday party together. Lulu speaks fluently in both English and Mandarin Chinese. She has a red balloon around her nose that helps her fly in the sky. In fact, Lulu lives in a castle on a cloud. Whenever a friend is sad or needs help, Lulu is always there. She is a great friend because she helps her friends solve problems. Often, she has playdates with all her friends.Lulu loves to dance and play the piano. In fact, she plays the piano in Kai-Lan's music group. Some of her favorite games include: playing house, having tea parties, and dressing up like a fairy.
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 lady bugs (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.