Ryū Sanada stands 179 cm tall with a fit build, shaved black hair, and sharp brown eyes, closely resembling his father Genji Sanada. Born on December 2 as a blood type B Sagittarius, he embodies a quiet, reserved demeanor and lives by the philosophy of "work silently," reflecting his earnest diligence. He typically wears his Kitahoro High School uniform, baseball gear, or casual black, gray, and white attire. Raised in a ramen-shop family, Ryū is the son of Genji and the late Tetsuko Sanada, who died during his third-grade year—a loss that deeply affected him and his childhood neighbor Chizuru Yoshida. The two have leaned on each other since childhood, with Ryū harboring long-term romantic feelings for her. He prioritizes Chizuru’s emotional well-being, comforting her during distress yet encouraging her to express anger healthily. Academically capable, he passes exams without remedial classes and plays for the school baseball team, where he befriended Shōta Kazehaya in middle school. Ryū aims to attend university for baseball, a plan that startles Chizuru, who expected him to stay in their hometown. After a loss in the North Hokkaido tournament sparks fears his baseball career might end, Chizuru reassures him, leading to a shared promise to run his family’s ramen shop together. Highly perceptive of others’ emotions—especially Chizuru’s—Ryū communicates effectively despite sparse words, bonding with the equally quiet Sawako Kuronuma. He enjoys napping, adores animals (distressed when separated from Shōta’s puppy), and struggles to remember names except for close friends like Chizuru, Shōta, Sawako, and Ayane Yano. Though he respects his older brother Toru, Ryū initially feels jealousy over Chizuru’s past crush on him; Toru believes Ryū and Chizuru would make a good couple. Ryū’s romance with Chizuru evolves gradually. During a school trip to Okinawa, he rejects another girl’s confession by stating he likes someone else—later revealed as Chizuru. When she reacts with awkwardness and denial to his direct confession, her feelings surface as she tearfully begs him not to leave for university. After Ryū confronts her, she reciprocates, leading to a kiss and relationship. Their bond deepens at their childhood refuge, a dock, where Ryū confides his baseball fears and vows to return after university to build a life with her, cementing their transition from friends to partners. His journey underscores quiet strength, loyalty, and balancing personal aspirations with enduring bonds.