On his way from Kyoto to the Eastern provinces, a traveling priest (waki) passes by Aono-ga-hara in Mino Province (now Ōgaki City, Gifu Prefecture). While there, he is approached by an unfamiliar monk (shite in act one) who asks him to perform a memorial service for the dead. The traveling priest follows the monk to his hermitage. Once inside, he is astonished to see various weapons propped up against the wall. In response to the priest's bewilderment, the monk explains that he needs the weapons to fight off the bandits that roam the area.
As soon as the monk invites the priest to rest for a while, the hermitage disappears without a trace, and the traveling priest finds himself sitting in the shade of a pine tree in the middle of a grassy field. It has all been an illusion.
The bemused priest is then approached by a man (ai) living in Aono-ga-hara. The local tells him that long ago, when Kaneuri Kichiji and Ushiwaka (later known as Minamoto-no-Yoshitsune) were staying in this area, the thief Kumasaka Chōhan and his gang broke into their inn. However, the bandits were quickly dealt with by Ushiwaka. Before leaving, the local man recommends that the traveling priest hold a memorial service for Kumasaka.
Later the same night, the traveling priest begins chanting his prayers under the pine tree. As the winds blow through the grassy plane, the ghost of Kumasaka Chōhan (shite in act two) appears. Swinging his naginata halberd left and right, the thief recounts how he broke into the inn where Kichiji and his men were staying, and engaged Ushiwaka in a duel to the death.
As dawn breaks, Kumasaka asks the priest to keep praying for the repose of his soul and vanishes into thin air.
Noh has a "still" and an "active" side. Elegant plays such as "Matsukaze" and "Izutsu" represent the "still" side, while "Kumasaka" with its speed and vigour represents the "active" side of Noh.
The shite in the first act performs without a mask - a style known as ‘hita-men’. It is quite a rare sight for the shite and waki to be dressed in the same type of costume - that of a Buddhist monk or priest.
For the role of Kumasaka's ghost, the shite in act two wears a mask called ‘Chōrei-beshimi’. It is a mask with piercing eyes, pursed lips and a somewhat charming face - despite its forceful expression.
Naturally, the highlight of the play is the moment where Kumasaka recounts his story while wielding a naginata halberd, the focal point being his energetic gestures and masterful handling of the weapon.
During the narration, Kumasaka boasts about his strength - he mimics catching and throwing a demon with the words: "I can grab it in the air and shred it to pieces". Especially impressive is the episode where he hides the halberd behind his back and faces Ushiwaka while using a door plate as a shield.
The final scene, where the narration ends and Kumasaka quietly disappears after asking the priest to pray for his soul, evokes pity and sorrow because of the contrast it creates with the energetic performance before it.
Another Noh play, "Eboshi-ori", is based on the same event as "Kumasaka", but it recreates the actual incident - a genre known as Genzai-Noh, or "real-world Noh". In it, the characters of Kumasaka and Ushiwaka are living human beings who battle on the stage (with the other bandits also joining the fight).