In between winning Grand Slam titles and gold medals, tennis champion Serena Williams, 40, has penned her first children's book. This week, Williams made public the news of her upcoming book, titled The Adventures of Qai Qai, scheduled for publishing on Sept. 27, 2022, by the MacMillan imprint Feiwel and Friends. Yesenia Moises will serve as the illustrator. 

The picture book's characters are based on personas created by entertainment technology company Invisible Universe, for which Williams is a partner and investor.

The Adventures of Qai Qai will focus on a doll that both Williams and husband Alexis Ohanian, 38, gifted their 4-year-old daughter, Alexis Olympia Ohanian Jr., some time ago. 

Williams is in charge of the Instagram account for Qai Qai, which has thus far amassed about 353,000 followers.

"People follow Qai Qai's social media accounts for laughs and trending dance moves, but she represents something much deeper than that. Qai Qai has an infectious spirit and models a belief that anything is possible. This book reflects the lessons she teaches and embodies and we hope others can walk away inspired after reading 'he Adventures with Qai Qai," said Williams, according to Good Morning America.

"Storytime is such an important pillar of our bedtime routine, like so many others around the world ... Qai Qai is a special member of our family and we hope The Adventures of Qai Qai will give others a new way to welcome Qai Qai into their own home," reads an official statement from Williams, released by People magazine.

“I know one thing four years ago that was really important to us was to make sure that Olympia had a Black baby doll … and have that be a very important first doll for her, if for no other reason than to just expose her to something that can hopefully break a cycle that we know exists. The Baby Doll Test has been used as an example for displaying the problems of societal discrimination and how hard-coded that gets into culture.” said Ohanian, according to People. 

The upcoming book will be devoted to every little girl.

"This book is dedicated to all little girls ... let this book be a constant reminder that you can do anything you put your mind to. Imagine it, believe it, do it," wrote Williams in her statement. 

Ohanian professed that many people worldwide deeply relate to Qai Qai.

"Very quickly we started to see this story play out online, of people who were just so enamored with this doll and were really excited to hear about the stories and adventures she was going to go on," said the Reddit co-founder, according to People. 

"I think there's a lot of people who have resonated with this idea of a really mischievous, and fun, and clever, and brave, and strong little girl doll and I'm excited to see all the places she goes and I do hope it can inspire kids — boys, girls, Black, white — all over the world to just have fun and dream," he added. 

Even though Williams was already a published author when she released her memoir, On the Line in 2009, this is her first children's book.