Sugawara denju tenarai kagami (Mirror of learning & transmitting Sugawara's secrets of calligraphy: 菅原伝授手習鑑) is based on legends surrounding the life of Sugawara Michizane (845-903: 菅原道真), also known as Kan Shôjô (菅丞相). Founder of the Kanke school of calligraphy and a favorite of Emperor Daigo, Sugawara ran afoul of an envious political rival named Fujiwara no Tokihira (Fujiwara no Shihei in the play) and was exiled to Kyûshû. After Sugawara's death, plague and drought spread throughout Japan and the sons of Emperor Daigo died in succession. The Imperial Palace's Great Audience Hall was struck repeatedly by lightning, igniting fires, and Kyoto was battered by rainstorms and floods. Attributing these calamities to Sugawara's vengeful spirit, the imperial court built and dedicated to him a Shinto shrine in 986 called Kitano Tenmangu (北野天満宮) in Kyoto. The court also posthumously restored his title and office, and removed records of his exile. Sugawara was deified as a Tenjin (Heavenly [Sky] deity: 天神), and many Shinto shrines in Japan were and continue to be dedicated to him.
In the play, Sugawara is a calligraphy master and Minister of the Right who shares power with Shihei, Minister of the Left. Sugawara is arrested on a trumped-up charge of plotting to overthrow the emperor and becomes the target of an assassination plot headed by Shihei. Sugawara is exiled to Kyûshû, where he dies cursing Shihei. Ultimately, the villain is slain by the calligrapher's son, Kan Shûsei, the house of Sugawara restored, and Sugawara pronounced a deity.
Shabito Sakuramaru (舎人桜丸) was one of triplets (Umôemaru, Sakuramaru, and Matsuômaru), sons of Shiradayû, who was Kan Shôjô's seventy-year-old retainer. Their names derive from Shiradayû's favorite trees: plum (ume: 梅), cherry (sakura: 桜 or 櫻), and pine (matsu: 松). Each son is a loyal retainer to one of the play's chief characters (Kan Shôjô, Prince Tokiyo, and Shihei, respectively.) The triplet's are performed with contrasting personalities and differing kumadori face makeup; Umôemaru is acted in the heroic aragoto-style (rough stuff: 荒事), Sakuramaru in the more gentle or romantic wagoto manner ("soft-stuff": 和事), and Matsuômaru in the fashion of villains (katakiyaku: 敵役 or more specifically, hagataki, evil retainers). The roles of the three brothers were inspired, so it is said, by the birth of triplets (a rare occurence in Japan) in the Tenma district of Osaka.
In Act I, Sakuramaru runs into trouble after arranging a meeting by the Kamo River in Kyoto between his master Prince Tokiyo, hated by Shihei as a competitor for the emperor's throne and an ally of Sugawara, and Sugawara's daughter, Princess Kariya. She is a commoner adopted into the court and thus not worthy of marrying a nobleman, so their love is scandalous. Sakuramaru becomes distracted when he has a dalliance with Kariya's maid, and makes matters worse for his master when he leaves to deal with a fight breaking out nearby. Meanwhile, unknown to Sakuramaru, a spy working for Shihei named Kiyotsura sees the couple and runs off to report them to Shihei, whereupon Shihei's men advance to arrest the lovers. When Sakuramaru returns, he finds the prince and princess have escaped. His guilt over abandoning his lord leaves him determined to take his own life in expiation. Things get worse for Sugawara when Shihei’s spies capture Tokiyo and Kariya. Tokiyo is taken away and Kariya removed to the care of her older sister, Tatsuya. The love affair is then used to disgrace Sugawara when Shihei falsely accuses Sugawara of coveting the throne through the marriage of Kariya to Tokiyo. In Act III, after his father's birthday celebration, Sakuramaru finally atones for bringing disgrace upon Tokiyo and Sugawara by commiting seppuku (incision of the abdomen or ritualized disembowelment: 切腹).
Sakuramaru stands by a fence beside a flowering cherry tree. His red top robe is patterned with sakura.
References: KNZ, no. 282; NKE, pp. 615