Sakuta Azusagawa, a socially withdrawn high school student, navigates supernatural phenomena tied to emotional turmoil called Adolescence Syndrome. His journey stems from a traumatic event involving his younger sister Kaede, whose severe cyberbullying-induced injuries and memory loss left him with three claw-like chest scars—physical manifestations of his own syndrome that resurface during emotional stress.

A pivotal encounter with Shoko Makinohara on Shichirigahama Beach reshaped his perspective; her counsel to embrace kindness forged his compassionate resolve. Despite being branded violent by the fabricated "Hospital Incident" rumor, Sakuta remains unfazed by societal judgment, valuing only the trust of his inner circle.

Beneath his pragmatic, sarcastic exterior lies unwavering selflessness. He aids those afflicted by Adolescence Syndrome, such as Mai Sakurajima, an actress erased from public consciousness, and Tomoe Koga, a classmate ensnared in a time loop from her insecurities. Sakuta merges logical reasoning with emotional acuity, often defying social conventions to resolve crises. His bond with Mai blossoms into a supportive romance, each tempering the other’s vulnerabilities.

Central relationships include his protective guardianship of Kaede, supporting her recovery from dissociative amnesia and school reintegration, and his enigmatic ties to Shoko, who reemerges during his grief. Shoko’s significance deepens through timeline complexities and her heart condition, where Sakuta’s choices dictate her survival and his destiny.

Later, as a college student, he continues confronting Adolescence Syndrome while navigating adulthood. His focus shifts to reconciling past wounds, particularly through Shoko, whose existence mirrors his unresolved guilt and quest for redemption. This evolution highlights his growth from a high school outsider to someone confronting existential duties, yet retaining his signature wit, self-sacrifice, and steadfast loyalty.