The play "Sugawara Denju Tenarai Kagami" was originally written for the puppet theater (Bunraku) and staged for the first time in the 8th lunar month of 1746 in Ôsaka at the Takemotoza. It was adapted for Kabuki the following month and staged for the first time in Kyôto at the Kitagawa no Shibai, produced by Nakamura Kiyosaburô I [casting]. It was also performed for the first time in Edo, at the Ichimuraza, in the 3rd lunar month of 1747 [casting].

This great play is based on the life of Sugawara no Michizane (845~903), a renowned scholar who was promoted up to the prestigious rank of udaijin ("Right Minister", one of the 2 close advisors of the Emperor). Falsely accused by Fujiwara no Shihei, the "Left Minister" (sadaijin), of trying to hatch a plot with Prince Tokiyo to seize the power, Sugawara no Michizane was exiled to Kyûshû. He dedicated his last years in writing poems, expressing both his homesickness and his innocence. After his death, the Emperor's residence was often struck by lightning and people thought it was done by the vengeful spirit of Sugawara no Michizane. A shrine was built in Kyôto to appease the spirit, the Kitano Tenmangû, and Sugawara no Michizane was revered as a the God of calligraphy. In the play Sugawara no Michizane is called Kan Shôjô.

"At the time when the authors were working on the play, a great stir was caused in Ôsaka by the birth of triplets. It was therefore decided to make use of triplets in the new production and thus it was that Matsuômaru, Umeômaru and Sakuramaru came into being. For the purpose of the story, the triplets are the sons of Sugawara's retainer, Shiratayû. When they were born, Sugawara stood sponsor to all three and named them after the trees he loved best, Matsu (Pine), Ume (Plum) and Sakura (Cherry). On their father's retirement, Umeômaru took his place as Sugawara's personal retainer. At the same time his two others brothers were found equally worthy employment, one as the retainer of Prince Tokiyo and the other in the household of Sugawara's colleague, Fujiwara no Shihei. When Shihei's jealousy brought about Sugawara's downfall, the triplets became the victims of divided loyalties" (Aubrey and Giovanna Halford in "The Kabuki Handbook").

Kan Shôjô's only son, Kan Shûsai, has been in Seriu village under the shelter of Genzô who was once one of the loyal retainers of Kan Shôjô. Kan Shôjô has been trapped and banished to a far province in Kyûshû. One day Genzô is called before the chief magistrate of the village and ordered to kill Kan Shûsai and bring his head to the authorities. He comes home with a sad look and tries to find a proper child in his school who can be killed in place of Kan Shûsai. Then Genzô's wife Tonami appears and reveals that a short time ago a noble woman like a warriors's wife came to ask for permission for her son's enrollment to the school. Kotarô is the son's name. Genzô makes up his mind to kill him instead of Kan Shûsai thinking he is noble enough to meet Kan Shûsai. He confesses this to his wife. He feels deeply sorry for Kotarô, but he can't overcome his great obligation to Kan Shôjô.

In the meantime Genba comes to the school with his men to ascertain whether Genzô did his duty. Genba is a vassal of Shihei, who set the trap and landed Kan Shôjô in a difficult situation. With Genba is Matsuômaru. He follows in a palanquin, for he must make it known that he is ill. He has come to make certain that it is Kan Shûsai's head, since he was once a guardsman of Kan Shôjô. The boys of the school are called out one by one, scrutinized by Matsuômaru and Genba, and released. Genba questions Tonami suspiciously about the number of students. There seems to be one desk too many. Kotarô's new desk still stands in the room. Tonami readily admits that it is Kan Shûsai's. Matsuômaru recognizes it and knows secretly that his son, Kotarô is in the school. Genba gives Genzô an empty head box, bidding him delay no longer. Genzô takes the box up and goes into the inner room. When a sound comes from the inner room, which means his son is killed, Matsuômaru can be seen to shudder quietly, but he quickly controls himself. Genzô returns with the box and sets it before Matsuômaru for inspection. Genzô kneels down and watches the inspector intently with his hand on his sword hilt. If Matsuômaru sems to deny that the head is Kan Shûsai's, Genzô intends to cut him down instantly. Genba's guards close in on Genzô with their weapons drawn, ready to kill him if he has attempted a fraud. Matsuômaru himself is not certain what he will find in the box. He slowly lifts the cover off the box. When Kotarô's head is revealed, he gazes upon it and says in a firm voice:"This is indeed the head of Kan Shûsai. There is no mistake". After this, Genba and his men leave along with Matsuômaru. Genzô and his wife then call Kan Shûsai from his hidding place and weep with relief that he is alive.

In the meantime, Matsuômaru's wife and Kotarô's mother Chiyo is seen approaching the gate. She calls "my dear son Kotarô, Kotarô, Kotarô!". Genzô, in desperation, tries to kill her. Chiyo barely escapes the sword blows and shows him a shroud of a little boy and flag which reads "Lord have mercy upon me". Genzô stands back and is dumbfounded. He asks "whose child was this?". Matsuômaru appears saying "My son! my son, Kotarô died gloriously and usefully". He explains the details of the matter. Even after becoming a follower of Shihei, Matsuômaru has wanted to repay his ex-master Kan Shôjô's kindness to him. Finally on this day he happened to know Genzô's predicament and was able to persuade his wife to sacrifice their son for Kan Shûsai. When he asks Genzô whether Kotarô dies worthily, Genzô answers "Honorably ... When I told him he must die, he smiled". Matsuômaru and his wife weep in sadness and joy to hear that (ôtoshi). Matsuômaru takes heart and summons his palaquin. From it steps Sonoo-no-Mae, Kan Shôjô's wife and Kan Shûsai's mother. Kan Shûsai comes in. Mother and Son comfort each other. They light a sacred fire to honor Kotarô's soul.

This summary has been written by Watanabe Hisao, edited by Jeff Blair and Shôriya Aragorô [website]