Ainu communities along the Hokkaido coast built a maritime economy around what the sea offered, and Repun Kamuy is the figure oral tradition credits with offering it. Whales in particular were understood not as animals simply caught by human skill but as beings sent deliberately toward the shore by Repun Kamuy, so that a beached whale, whether it had died naturally or been driven in, was received as a direct gift rather than as a stroke of luck, and treated with the ceremonial care the Ainu extended to any kamuy who gave its body for human use. The orca form associated with Repun Kamuy fits this role naturally, since orcas were themselves observed driving smaller whales and fish toward shore in the course of their own hunting, an ecological behaviour Ainu tradition reads as the deity's deliberate provision.
The relationship between Repun Kamuy and the human communities who depended on the sea was understood as reciprocal rather than one directional. Proper conduct toward the sea, correct disposal of animal remains, and ceremonial acknowledgement of what had been received were all part of maintaining the relationship that kept the kamuy favourably disposed. This mirrors the structure of the Ainu relationship with Kim-un Kamuy, the mountain and bear kamuy, whose gift is game rather than fish, so that Ainu subsistence as a whole is framed less as extraction from a passive nature and more as an ongoing exchange with kamuy who choose to give.