Mai is used to spending every summer in Mystic, Connecticut visiting family friends, and hanging out with her best-friend-since-birth, Zach Koyama, has always been the best part. Then two summers ago everything changed. Zach humiliated Mai and proved he didn’t have her back. So when Zach’s family moved to Japan and they missed last summer, Mai was nothing but relieved. But this year, the Koyamas are back, and if Mai has to spend the summer in Zach’s presence, the least she can do is wipe away the memory of his betrayal by coming up with the perfect plan for revenge.

But memories are funny things. They have a life of their own, bubbling up when Mai least expects them. Some are sweet and some are sour. And none of them perfectly reflect the boy Zach has become. Mai thought she had Zach pegged, but as the summer unfolds she begins to realize that there are three sides to every story—his, hers, and the truth.

How did Sweet and Sour come to life? 

This book was a surprise for me and also a saving grace for me. The writing of it was entirely done during the pandemic. To be able to sink into Mai’s world—a 12-year-old who had all the freedoms we had before we were sheltering in place—gave me peace and freedom too. To get up and work on this every morning saved me. I was able to live through Mai’s eyes and Mai’s life.

The concept about sweet and sour wasn’t on purpose. I wanted to write about friendships and misunderstandings that happen in every relationship. Sometimes those misunderstandings blow up, and if you sit with them too long, you start telling stories in your head about what the other person was thinking—and that becomes the truth to you. How you misconstrue what other people do and what they were potentially thinking can change over time in your head.

Amai in Japanese means “sweet.” She’s sweet; maybe Zach is sour—and then the title came to me before I finished writing the book, and that led me to flashbacks, that way the reader could get the truth of how their friendship unfolded.

It’s how I write all my books: I start with a premise and characters and it kind of goes from there.

How does identity and representation show up in the story?

I am a third generation Japanese American, which means my grandparents immigrated to the States—that’s called sansei, which means third generation. I was born in San Francisco and grew up in Los Angeles and had a very large Japanese American community—and because of this, I grew up not feeling othered. I remember going to school with shirts in Japanese; I was proud of being Japanese American and I identified as Japanese American but in my head I was just your basic American kid. It wasn’t until I moved that I realized people look at me differently.

And then when talking to other Asian American friends, I realized that what they experienced in terms of feeling different wasn’t my upbringing. I don’t remember being teased or called out. When I write my books, for representation, I have infused all of my experiences in the characters—and mine are not that of ALL Japanese Americans. This is just one slice.

Amai identifies strongly with being Japanese American and her friend Zach, who has gone to Japan for two years with his family, makes Amai think about the experiences he has had that she hasn’t.

There are some microaggressions—for example, when a new friend comments that the Japanese potato chip flavors are “weird”—but Mai calls her out. That’s just one reaction. Sometimes it doesn’t go that way. There are others in the book that include blatant racism, and people who do not want to change their thinking.

How is friendship explored in this book?

All of my books talk about friendships because that’s what fascinates me most about being human: how we all relate to one another. Each relationship is different. Mai and Zach are childhood friends. They’ve known each other since birth and something happens. Zach humiliates Mai and she is glad they’re apart for a summer and they have to come back together. It’s a story of what is forgivable. I wanted to think through, what does forgiveness look like?

She cannot ever imagine forgiving Zach but Mai starts to question her memory. Maybe all her angry feelings have blotted out all of the good things. I think that happens to everyone. I’ve done it to friends. I’ve said things to someone and not realized it and it’s not until the friend says, “By the way, you hurt my feelings”—and then I can learn and grow from it. Sometimes we do something unintentionally. And that is the crux of the story. Until you talk to them and have an honest conversation, that is the sweet and sour of all friendships.

This book has a little romance, too. 

As always with my middle grade books, there’s a throughline of first romance, where the feelings are so real and so strong and so genuine. It’s a form of respect to acknowledge what young people are feeling. What a nice way for readers to explore emotions. When you’re reading a book, it’s a safe way to acknowledge your own hopes and feelings and fantasies between the pages.