In the fourth season of Sex Education, Cal Bowman is a new student at Moordale Secondary School who identifies as non-binary. They become close friends with Jackson, but their friendship becomes complicated after feelings get involved. At the end of the third season, Cal tells Jackson they should remain friends, and Jackson seems to be okay with this decision. In the fourth season, Jackson tries to distance himself from Cal, but Cal decides to move on and focus on transitioning. They start taking testosterone and notice significant changes in their voice, sex drive, and physical appearance.

In the season 4 finale, Cals mom shows up at Cavendish College and tells Cals friends that Cal is missing. So, they start a search for Cal. Cals gender dysphoria got really bad in the last couple of episodes, and their anxiety about not being able to get the medical care they needed skyrocketed. Cal went to the mall, ditched their backpack, and took off. The whole school started a search party. They were technically found twice: once by Eric who just happened to be passing by, and then by Jackson who knew where theyd be. The three sat and talked for a minute. Jackson and Cal have a history, but that trio hadnt really interacted before. At the end of the episode, the school decided to raise money for Cals top surgery.