Akadō Suzunosuke Konno bears the family name Kinno, with "Akadō" derived from his striking red kendo armor—a legacy from his late father, Tetsunosuke Kinno. Raised by his grandfather Tetsusai in Itako without knowledge of his parents, he journeys to Edo following Tetsusai's death. There, he trains under swordsmaster Shūsaku Chiba at the Hokushin Ittō-ryū dojo, where his father once studied. His mother, Osuzu, works as a tailor in Edo after an earlier separation from the family for undisclosed reasons.

Suzunosuke joins the Chiba Dojo to master swordsmanship and become Japan's greatest swordsman. He trains rigorously in the "Shinku Giri" (Vacuum Slash), a technique inherited from his father, and later acquires the advanced "Jumonji Giri" (Cross-Shaped Slash), executed with dual swords. His path features fierce rivalries, most notably with senior disciple Rainoshin Tatsumaki; their clashes culminate in reconciliation after Suzunosuke defeats him.

He forms key bonds: a turbulent friendship with Matsunosuke Ooki, initially strained by Matsunosuke's belief that Suzunosuke killed his father, and a supportive connection with Sayuri Chiba, Shūsaku’s daughter and a skilled naginata practitioner. Mentors Shūsaku Chiba and Oshinosuke Yokoguruma—the dojo’s head instructor and his father’s close friend—guide his growth.

External threats loom, including the Kimento (Demon Mask Group), which schemes to overthrow the Edo Shogunate and repeatedly tries recruiting Suzunosuke and Rainoshin. Film adaptations introduce supernatural foes like the One-Legged Demon and Three-Eyed Birdman, members of antagonistic groups targeting him. His travels beyond Edo, depicted as a road-movie narrative in anime, expose him to diverse regional conflicts.

Suzunosuke embodies perseverance, confronting betrayal, familial loss, and moral trials while steadfastly upholding justice. His evolution shifts from a trainee focused on personal mastery to a protector actively defending societal stability against large-scale conspiracies.