The following version of this book was used to create this study guide: Reyes, Sonora. The Lesbiana's Guide to Catholic School. HarperCollins. 2022. Kindle.

Yami, the teenage protagonist, narrates the novel in first-person present. The book starts in the middle of the summer before her junior year. She fell in love with her ex-best friend, Bianca, but when she revealed her feelings to Bianca, Bianca outted her to all their friends. Luckily, Yami’s brother earned a scholarship to a prestigious Catholic school on the north side of Phoenix. Since he has been getting in lots of fights, Yami’s mother insists that she transfer, too, to keep an eye on Cesar. This works perfectly for Yami, who does not want to return to her old school and face Bianca. She gets a job at a coffee shop to help pay for her tuition, but then Bianca comes in and Yami quits on the spot rather than face her. When she gets home, Yami punches a mirror. Her mother grounds her and tells her she must find another job. Yami tries applying everywhere, but no one wants to hire her, so she decides to revamp her mother’s jewelry-making hobby and start an online business. Yami’s videos and advertisements go semi-viral, and she ends up selling tons of pieces for her mom.

Yami and Cesar start at Slayton Catholic School. Yami meets a cute girl, Jenna, and hangs out with her friends, Karen and Emily. However, she secretly admires a girl named Bo, who is a proud lesbian that gives a presentation on abortion rights. At lunch, Yami hangs out with Cesar and his new friend, Hunter, who develops a crush on her. The next day, Yami decides to wear her hoop earrings and Jordans, but Karen and Jenna tell her she looks ghetto. Yami decides she does not want to be friends with them. In Language Arts, the teacher makes the students argue the pros and cons of gay marriage, and Yami cries in the bathroom afterwards. At school the next day, she sits with Bo, and the two become friends.

Cesar gets detention for sleeping in class and lies to his mom, telling her that he has joined the football team. One day, Yami goes home early and catches him kissing his friend from their old school, Jamal. Their mom walks in right after, and Yami lies and explains that Jamal is her boyfriend. Their mother invites Jamal over for dinner that weekend. Cesar admits to Yami that he is secretly bi and has been dating Jamal for a year, and she tells him she is gay. Yami and Jamal start a fake relationship.

Back at school. Bo draws a portrait of Yami that she does not let her see. At lunch, Jenna asks Bo to homecoming as a prank, and Bo gets super embarrassed. She runs out to her car to ditch, and her best friend, Amber, and Yami go with her. They watch a scary movie in the theater and hold hands. At homecoming, everyone couples up, so Yami goes over to Bo’s house to ditch the dance together. Yami starts thinking about kissing Bo. Yami panics and tells Bo that she is straight, which offends Bo, who says she does not like Yami like that. Yami invites Bo to come with her to the afterparty with Cesar, but Bo declines and tells Yami to leave.

Yami picks up Cesar and they go to the party together. Yami gets drunk and Hunter tries to kiss her, but she tells him she is gay. He tells her he is a virgin, and they agree not to disclose one another’s secrets. The police come to the party, but they leave after telling everyone to turn the music down. Yami goes out to the car and drunkenly texts her dad, who lives in Mexico, and tells him she is gay, then calls Bo and leaves a voicemail telling her she likes her and that she is gay. Bo calls Yami back and then comes to pick her up. When Yami wakes up in the morning, she deletes the voicemail and tries to call her dad, but he ignores her.

Jamal comes out to his parents and gets kicked out. Because she still thinks he is Yami’s boyfriend, Yami’s mom says he can stay with them. However, after going to Confession at school, Cesar and Jamal break up, and Jamal moves in with his cousin.

The continued silence of her father makes Yami panic, so she starts selling extra jewelry so she will have enough money to afford an apartment in case her dad tells her mom she is gay and Yami gets kicked out. Their mom gets tickets for Yami and Cesar to visit their dad for winter break, but Yami says she cannot go because she has homework. Their mom agrees to use the ticket herself, and Yami stays at Bo’s house for all of winter break.

After they get back from Mexico, Cesar tells Yami that their father made homophobic comments about Yami while he was in Mexico. Yami starts working for Bo’s mom as a secretary to save up even more money. For her birthday, Yami decides to skip school with her friends, but everyone gets caught except Bo and Yami, so they spend the day together and pretend to be a couple. When Bo drives Yami home, the girls kiss and Yami admits she is a lesbian. However, Yami gets a call from Jamal telling her that Cesar is in the hospital.

When Yami arrives, she learns that Cesar has been feeling suicidal for a long time, and he finally called Jamal asking for help. He is admitted to Horizon Behavioral Health Facility for three days. Their mom goes through his phone and learns that he has been in a relationship with Jamal. Yami admits that she is a lesbian to her mom, and her mom reacts better than expected.

When they go to pick up Cesar to bring him home, Yami’s mom decorates the house full of rainbows and bakes desserts to show her children that she supports them. She also tells off their father, and refuses to support him in his homophobia.

Yami decides that she wants to officially ask out Bo, so she does so at the big art show at school. Bo says yes, but then the principal bans them from attending prom together because it goes against the “principles” of Catholicism. Bo’s parents agree to host anti-prom at their house, and tons of students join in. Bo and Yami dance, then tell one another they are in love.