Sanjuurō Sakura is the magically rejuvenated identity of elderly kendo master Sanjuurō Tsurugi. This transformation occurs when Tsurugi, lying beneath his garden's magical cherry blossom tree and envying its vitality, awakens biologically reversed to age 16-17 – matching his granddaughter Michiko's age. He possesses a teenage physique while retaining his core personality: pride in swordsmanship and deep concern for Michiko. Initially bewildered, Sakura confirms his transformation upon seeing his reflection. He embraces his youth, exploring Tokyo and indulging in activities like baseball, bowling, and eating at McDonald's. Wearing traditional kendo attire leads staff at Michiko's school to mistake him for a student. There, he overhears kendo club member Tatsuya Nakadai plotting to harass Michiko and intervenes protectively. Sakura confronts Nakadai but hesitates during their duel upon hearing Michiko support Nakadai, resulting in his injury. After recuperating, he follows Michiko home and faces Nakadai again. Nakadai escalates the conflict using live blades, endangering Michiko. Sakura struggles until Michiko throws him his original katana. He then executes his signature "Hikken - Cherry Blossom Storm," disarming Nakadai non-lethally by shredding his uniform and shearing his hair. Later, Sakura reflects near the cherry tree, acknowledging its role in his transformation and expressing fulfillment from reliving youth and protecting Michiko. He consciously reverts to his elderly form. When Michiko questions Tsurugi about Sakura's disappearance, he deflects humorously, privately amused by her remark that Sakura was "much cooler" than him.