Alma is a 12-year-old fascinated with graveyards… especially discovering the one where her father is buried. This is just one thing her mother refuses to discuss with Alma: she won't talk about who her father was, how he died, or where he is buried. She does not speak of his side of the family or why her stepfather, Adam, suddenly drops out of their lives. No time is a good time for questions, and Alma is left to figure out what is happening while it is happening. 

Contrast this with the Alma's best friend, Julia, who is originally from Korea. She was adopted by a couple in the United States, whom she loves, but cannot help missing her birth mom, whom she has never met. Longing to establish a connection with her mother, Julia understands Alma's quest to find her father's grave site; she knows just what it feels like to have an MIA parent.

Then, Julia is suddenly whisked away to Portugal to live with her father's side of the family, including her grandmother, Avo, and her cousin, Leonor. Julia does not understand Portuguese, communicating with Avo via miming and hand gestures. The teen meets new kids at an English-language school and learns to speak Portuguese, haltingly. Meanwhile, Alma yearns to forever be with her friend, Julia, and to find her father.

One Speck of Truth by Caela Carter, 2019

This was especially interesting because of the unique relationship between a Portugese girl and a Korean girl—and I love reading books about other countries. 

Caela Carter's website

Books about Portugal
 

High school sophomore Zona has never met her mother, who died when the girl was a baby. Life has always been simply her and her journalist dad. Like father, like daughter when Zona finally wins a coveted spot on the school newspaper. She had worked hard for the opportunity, only to have it snatched away all of a sudden and given to her best friend, Hilary. This becomes a slight point of contention between the two. 

Zona's dad decides Zona needs to explore her family roots in Greece. Her mother's family, whom she has never met and has never communicated with her or her father, awaits her on another continent. The teen is not exactly thrilled, to say the least, with the prospect of spending half the school year in Athens. Leaving Hilary and her other friends, the school paper, and life as she has known it in New York City, is something Zona fights against, tooth and nail, to the bitter end.

The bitter end leads her to Greece.

Which, Zona discovers, is not so bad…

Zona and her dad relocate to Greece, and the girl prepares to meet and fraternize with long-lost kin. Her cousin, Yiota, takes Zona under her wing immediately, and they explore Athens together as Zona's initiation to the country. At the Greek International School, Zona finds kids from around the world, such as Betony, Lilena, and the super-cute Giorgos. Life in Greece has some highlights, the teen discovers.

Sophomore Year is Greek To Me by Meredith Zeitlin, 2015

I loved the insider's look at Greek life and culture. It was interesting to learn about Athens and rural Greece from a fictional perspective. 

Books about Greece
 

Eddie and Marcus, white and black. Interracial friendships are not too common in the Queens neighborhood where these teens are growing up. Buddies on and off the basketball court, they go everywhere together, and converse frequently at school, home, and basketball practice and games. Their families are in constant contact with each other, and everything is going well in their lives.

Until the pair concocts a devious plan to steal a coveted pair of sneakers from a store.

Unsurprisingly, the cops nab Marcus first: he is the gunman, having shot someone during the theft, and is apprehended during one of his games. The news sends a chill throughout the entire team, but they still manage to win. Everyone is worried about Marcus and the events to come. Identified by the shooting victim, a local bus operator, Marcus knows, at least, the man has survived.

Eddie keeps his focus on the college scouts attending the game. He approaches a recruiting agent from St. John's University, and expresses his interest in the school. Unbelievably enough, the scout asks the teen to submit a letter of intent to keep the ball rolling. Eddie's elation about the school is tempered with the knowledge of his friend's problems—and the terror at the prospect of being discovered runs.

Black and White by Paul Volponi, 2005

This is the best work about juvenile justice that I have read since Walter Dean Myers' Monster.

Books about juvenile justice

Paul Volponi's website