4 ideas
The collection is arranged by geography, not theme: Tenjiku (India), Shintan (China), then Honchō (Japan). This order traces the dharma's eastward transmission, so a Japanese anecdote gains doctrinal weight by sitting at the end of a lineage that began with the Buddha. Local events become the latest instance of a universal pattern.
Nearly every tale opens with 'Ima wa mukashi' ('At a time now past') and closes with 'to namu katari-tsutaetaru to ya' ('so it has been handed down'). The opening puts the story in an indefinite past, and the closing presents it as received testimony rather than authored fiction. Together the two formulas give even strange or crude episodes the authority of a transmitted record.
The Buddhist tales argue that present suffering or prosperity follows directly from past deeds, often from a former life. A single sin, such as killing an animal, or a single act of devotion, such as copying a sutra, sets off a traceable chain of consequences.
The later Japanese sections include thieves, warriors, ghosts, tricksters, and sexual escapades, and many of them carry little or no doctrine. Placed beside the Buddhist exempla, these ordinary episodes read as the raw material of karma in action. Human folly, cunning, and desire become things to observe and judge rather than things too low to record.