Summary: Scenarios that describe concrete situations of software operation play an important role in software development and especially in requirements engineering. Scenario details should vary in content when described from different viewpoints, but this presents a difficulty, because an informal scenario from one viewpoint can not easily be transformed into a scenario from another viewpoint with consistency and assurance. This paper describes (1) a language for describing scenarios in which simple action traces are embellished to include typed frames based on a simple case grammar of actions, and (2) a method to accomplish the transformation between scenarios from different viewpoints based on the scenario description language.