Physics or Chemistry - 1 ª Season

Start of the course. Irene, a 27 year old girl wakes up in her bed with a boy next door who will turn out to be a student in her new job as a philosophy teacher. Blanca, who has always wanted to be a teacher, will discover that it is harder than she expected.

Some students of the school organize a petting party in the house of one of them. They advertise it with posters in the institute, but none of the professors knows what it consists of, only that it is of high sexual content. Paula is invited by Cabano to the party and, in principle she doubts, but Cova convinces her to go. For her part, Irene, although she had proposed that what happened with her student Isaac would not happen again, in the end she can not help it and falls back into temptation. She repents right away especially when Isaac's mother is going to talk to her about the change in her son's behavior. Blanca, the literature teacher, to get students interested in the topic of the class, tries to give them another point of view about "La Celestina", but, without eating or drinking it, the class becomes a debate about sex. The director finds out and offers Blanca to give talks to the kids about sex. But this idea overwhelms Blanca a lot, she knows that she is not the best candidate to give them. Jonathan realizes that Julio is denying his brother's death and wants to help him overcome it. For that, he begins to study the subject and asks for help from Blanca. Between them will arise an attraction that neither of them can deny. Roque tries to motivate Jan to continue drawing as he is very good at what he does. And he also asks him to be encouraged to tell the girl that he likes what he feels for her. But Jan at that time is worried about other things, has problems with Gorka and Cabano that continue to harass him. Olimpia is accused of racism by the students of the class, since they find a sheet written in her own handwriting with xenophobic qualifications to a student. Olimpia says she has not written that, and is being tricked, but many teachers do not believe her, including her husband, and will have to fight to prove her innocence

Blanca seeks to start a relationship with Jonathan. Irene discovers that she has an STD, so she will have to talk to Isaac. Gorka and Cabano are expelled three days because of Jan. Ruth chats on the web cam with a guy. Yoli discovers that the boy is Gorka, so Ruth starts to flirt with him.

Irene is determined to resign, but a virus has prevented Clara from reading her resignation email. Ruth tells that Roque has smoked at a party, so Adolfo gives the talk about drugs. Irene organizes a talk about homosexuality due to the bullying suffered by Fer.

Blanca and Irene still have problems. They have started circulating pictures of Irene nude. Meanwhile, she stays with her old boyfriend. Ruth has remained an orphan, Clara offers to welcome her. Julio is still obsessed with the death of his brother. Everything leads to Gorka, but he refuses to talk.