TV-Series
Description
Tsubasa Tanuma is a second-year student in Class 2-B at Shuchi'in Academy and Nagisa Kashiwagi's boyfriend. As the son of a hospital director, he is expected to succeed his father in the medical profession.

Initially introduced with straight black hair and a bland appearance, Tsubasa later transformed his look, changing his hairstyle, dyeing his hair grey (depicted as brown in the anime adaptation), and adding ear piercings. This change was driven by Nagisa's stated preference for a "bad boy" aesthetic, demonstrating his willingness to adapt for her approval. His personality remains fundamentally kind and easygoing; he rarely displays anger, even when openly criticized about lacking independence. Yet he displays unrestrained physical affection in public, including making out with Nagisa in front of the student council, and frequently boasts about their relationship, often visiting the council under the pretext of seeking romantic advice without genuine issues.

Their relationship began when Tsubasa confessed using the "kabedon" (wall slam) technique, a strategy suggested by student council president Miyuki Shirogane. After Nagisa accepted, they joined the Volunteering Club together. Tsubasa continued seeking guidance from Miyuki and Yu Ishigami on relationship matters like holding hands and understanding Nagisa's occasional anger. Their interactions included typical teenage challenges, such as Tsubasa hiring a private detective to investigate potential infidelity, later resolved through reconciliation.

Maki Shijo developed unrequited feelings for Tsubasa after witnessing his confession, though he remained devoted to Nagisa. Tsubasa later advised Ishigami on confession techniques, recommending the same kabedon method Miyuki taught him.

Their relationship progressed physically, with Nagisa revealing they began having sex approximately two months after their first kiss. By Chapter 274, Nagisa was confirmed to be three months pregnant with Tsubasa's child. Promotional artwork depicting the characters as adults shows them with multiple children, including a daughter named after Maki Shijo and Nagisa visibly pregnant again.