Merci Suarez is starting sixth grade and her second year at a private school called Seaward Pines. She and her older brother, Roli, are scholarship students, so they don’t always fit in with the other kids, who live in big houses and go on long expensive vacations. Part of their scholarship agreement requires Merci and Roli to complete service hours each school year.
On the first day of school, Merci finds out that her service assignment is with the Sunshine Buddies — a program that pairs new students with buddies for the first half of the school year. Merci is worried that being a buddy will cut into her time for after-school soccer practice. To make matters worse, Merci is the only girl to be paired with a boy for Sunshine Buddies, and Edna Santos, the most popular girl in school, won’t let her hear the end of it.
Merci lives in one of three identical pink houses on the same street. The other two house her grandparents and Aunt Ines and her cousins, 5-year-old twin boys. Merci knows she will have to baby-sit the twins when she gets home, but she is looking forward to her daily after-school chat with her grandpa, Lolo. She hopes he can help her feel better about the Sunshine Buddies and Edna’s teasing.
When she gets home, however, Merci sees a police cruiser in the front yard with Lolo and the twins in the back seat. The twins get out, and Merci rushes over to see what is happening. Her mom tells her to go watch the children while she talks to the police officer, but Merci feels that she is old enough to know about the matter, so she walks over to the police cruiser and begins to talk to Lolo, who is still in the back seat.
He explains that there was a misunderstanding. When he went to pick up the twins from school, he almost brought home a different set of twins, and they began to scream that they were being kidnapped. The police officer brought Lolo and the correct twins home so he could talk to Merci’s mom and sort everything out. Lolo says that he needs new glasses.
Merci still wants to talk to Lolo about her day, but he wants to be alone after the ordeal. The next day after school, Merci gets a chance to talk to him. Lolo listens sympathetically and states that he has a job for her that might cheer her up. Merci’s dad and grandpa have a painting company, and they’ve been hired to paint the bathrooms at a beach clubhouse. He says that if Merci helps, he will give her some money toward a new bike.
On Sunday morning, Lolo and Merci ride their bikes to a bakery to get breakfast for everyone. On the way back, Lolo crashes his bike. Merci has never seen Lolo fall before. Merci cleans the blood off of his chin and helps him to a bench while she checks his bike tires. Everything looks fine.
Before they finish the ride back to the house, Lolo makes Merci promise not to tell her grandmother. He says she worries too much and might not want them to ride their bikes together anymore. Merci doesn’t like lying to her grandma. They aren’t supposed to have secrets in their family, but she also doesn’t want to give up bike rides with Lolo, so she agrees.
At school the next day, Merci wracks her brain for a suitable Sunshine Buddy activity that she can do with Michael. During lunch Edna suggests that they should all go to the new Iguanador movie on Saturday night. Merci is not sure if her parents will let her go, but it would be a perfect opportunity to do something with Michael. Her parents agree that she can go if her brother comes, too. Merci and her friends have a good time at the movie and go to get ice cream together before heading home.
The next day in Ms. Tannenbaum’s class, Edna asks Merci to deliver a note to Michael. At lunch, Merci finds out that it was a love note asking Michael if he liked Edna. Before they head to their next class, Michael comes over to the girls’ table and says that he maybe likes Edna. Merci thinks that’s a dumb answer because you either like someone or you don’t.
When Merci, her dad, and Lolo arrive at the clubhouse for the painting job, Merci goes to the women’s restroom to start working on the trim while he and Lolo work on the men’s restroom. After a little while, Merci goes to find Lolo and her dad to remind them to take a lunch break. Her dad says Lolo went out on the porch. He suggests that Merci go tell Lolo that they are going to take a lunch break, while he finishes up a few things.
Merci heads out to the porch, but Lolo isn’t there. Merci begins to worry and tells her dad that she can’t find Lolo. He goes to look downstairs, while Merci searches the beach. She sees one of Lolo’s shoes and socks half-buried in the sand. She begins to panic but finally spots him on the pier with some fishermen. He is badly sunburned. Merci gives him his shoes and takes him back to her father. Lolo thanks her for being a good daughter and calls her by her aunt’s name.
The next day Merci asks her mom to sign a release form for the soccer team. The form has been on the fridge for weeks, but Mami still hasn’t signed it. Merci explains that tryouts are that day, and she needs the release form, but her mom states that they need Merci’s help at home right now, so she will have to wait until next year to try out. Merci is angry and crushed.
Later that day, Merci decides to blow off some steam by hitting a few baseballs before PE class. She knows she isn’t supposed to touch the equipment without adult supervision, but she figures nothing bad can happen. Michael is also there early and offers to pitch for her. She hits his first pitch, but the ball hits Michael in the mouth. He has to go to the nurse, and Merci is sent to detention for breaking the rules.
When Merci gets home that day, she is in a bad mood. She goes to Lolo and Abuela’s house to get the twins to baby-sit them. She opens their fridge to get a snack and sees Lolo’s glasses inside. Merci knows Lolo has been acting strange, but she is angry and scared, so rather than admitting that Lolo probably placed them in the fridge absentmindedly, she screams at the twins for hiding his glasses.
Every year Seaward Pines has a grandparents’ day. Merci has been looking forward to having Lolo and Abuela at school with her. Lolo is acting strange again, however. Abuela is telling him to get ready, but he keeps yelling that he doesn’t want to go. Eventually he gets so frustrated that he charges at her, and Merci worries that he is going to hit Abuela. Her brother stops him, and the family decides that Lolo and Abuela won’t be able to go to school with Merci.
Later that week, Merci and the rest of Ms. Tannenbaum’s class begin working on a booth for the school’s harvest festival. Ms. Tannenbaum offers the class extra credit if they come dressed as an Egyptian god or goddess and give a short presentation. Merci mentions that her grandma is going to make her costume, and Michael asks if Merci’s grandma can help with his costume, too. Merci is relieved that Michael isn’t upset about the baseball incident and decides that working on costumes together is a good Sunshine Buddy activity.
Michael comes over the next day to work on the costume, but Edna gets jealous that Michael and Merci are spending so much time together. The morning of the harvest festival, Merci leaves Michael’s completed costume in Ms. Tannenbaum’s room, while she goes to her first class of the day. When she comes back, the costume is destroyed and stuffed in the trash. Michael does his best to tape it together, but it’s still clearly broken. The rest of the harvest festival goes smoothly, but later Merci hears Edna and some other sixth-grade girls talking about a party that they’re having that night. Even most of the boys are going, but Merci isn’t invited.
As Merci and Roli are driving home after school, they suddenly see Lolo standing on a median in the middle of the road. Roli tries to drive over to him, but suddenly Lolo steps out into the road. Roli changes lanes in a panic and is rear-ended by another car. No one is seriously hurt, but Roli and Merci are distraught.
Later that night, Merci asks Roli what is wrong with Lolo and why he is acting so strangely. Roli explains that Lolo has Alzheimer’s disease. Merci is angry that her family has been lying to her for years about Lolo being sick. She is scared about Lolo continuing to change and forget things.
The next day at school, Merci gets chosen for an important role for Ms. Tannenbaum’s final class project. They are supposed to make a replica of an Egyptian tomb, and Merci is one of the three girls chosen to design the mummy and sarcophagus. Merci, Lena and Hannah decide to use plaster to create a mummy, but they need a model who they can put the plaster on until it dries. Edna volunteers. The project goes well initially, but Merci forgets to put Vaseline on Edna’s eyebrows so the plaster won’t stick to them. Merci has to cut Edna’s eyebrows off to get her out of the plaster.
Edna is angry with Merci, even though it was an accident, and reports her to the principal. The next morning Merci nervously shows up at the principal’s office, but he just pulls up security camera footage of Edna destroying Michael’s costume a few weeks before. Merci had forgotten that her teacher made her file an incident report about the costume. Edna gets detention, and Merci apologizes again for cutting off her eyebrows.
Edna starts being nicer to Merci, and the class’s tomb project is a huge success. Merci, Lena, Hannah and Edna even get their picture in the paper. The tomb project is the last assignment before Christmas break, and Merci is ready to spend the holidays with her family. She decides to make a scrapbook of family photos and memories as a gift for her family. She designs it especially for Lolo, to help him remember everything. Merci’s parents get her a new bike for Christmas. Merci decides that all of the changes she’s experienced this year are just like a harder bike gear and that she can handle whatever life has next for her.