When sixteen-year-old Lili Reed’s dad decides he needs an adventure, and his old friends the Takadas invite them to spend a semester in Japan, Lili is desperate enough to leave her carefully managed routine and give it a try. Because this has to work. Four years, five months, and twenty-one days ago, Lili learned you can lose everything in a single moment. That was the day her mom died. The day her dad started wrestling with depression. The day Lili learned she’d better keep her heart “together,” because her little sister Lennon needed her.

Tokyo, as it turns out, is just the adventure Dad and Lennon need: new sights, new foods, new friends, especially Aya, her Dad’s pretty new colleague who keeps coming around. But for Lili, it’s too many new things at once. She can’t figure out how to eat with chopsticks. Navigate the trains. Discern “great mysteries” like which carton has milk and which has liquid cherry yogurt. And why does every experience with a freaking toilet end in some kind of humiliating disaster? Even worse, Tai, the Takada’s seventeen-year-old son, always seems to be around for her cringe-inducing mishaps. Maybe his crooked grin is a bit distracting, but then he OPENS HIS MOUTH and turns out to be rude, opinionated (wrong), and way too observant of things Lili doesn’t want seen—personal things. Like her fractured heart.

But as weeks pass, and Lili’s dad becomes distressingly preoccupied with his new relationship with Aya, Lili finds herself wholly unprepared for the soul-crushing loneliness of navigating life in a new country with only six-year-old Lennon for company. And maybe Tai isn’t as bad as she thought? Especially when they make up ridiculous songs together on his guitar, making Lili laugh harder than she’s laughed in…well, a long time. But spending time with Tai reminds Lili of another, more open-hearted version of herself, one she hasn’t seen in four years, five months, and twenty-one days. And how can soul-crushed, cringe-magnet, trying-hard-to-keep-her-heart-together Lili deal with even one more “new thing,” especially something so easily lost in a single, tragic moment…as love?