A large portion of the standard Noh repertoire, the category known as mugen noh, dream or phantasmal Noh, follows a consistent structure in which a traveling priest encounters a local person who turns out, by the play's second half, to be the spirit of someone dead, still bound to the world by an unresolved attachment, grief, love, ambition, or a violent death, from their former life. The spirit reenacts or narrates that attachment for the priest, and the implied hope of the encounter, consistent with Buddhist teaching on attachment as the root of suffering and continued rebirth, is that being witnessed and prayed for will help move the spirit toward release rather than continued wandering. That structure gives Noh a religious function distinct from simple storytelling, closer to a memorial or intercessory rite performed in dramatic form than to theatre concerned only with plot, and scholars of the tradition read its formal restraint, minimal action, long silences, a chorus rather than dialogue carrying much of the narrative, as suited to that meditative, almost liturgical purpose.
Okina stands apart from this repertoire entirely and the tradition marks the distinction explicitly, calling it Noh and yet not Noh: it has no plot and portrays no character, but has the lead performer don the mask of an old man on stage, an act unique to this piece, and dance a blessing for peace, harvest and long life, prepared for through ritual abstinence and treated, in Noh's own self-understanding, as housing a deity for the performance's duration rather than depicting one.