Think of it as: Tosai is a koi that has had its first season of growth, Nisai is second season of growth, etc. The conventional 'season' is May-October. In the Spring after the first season of growth, the tosai becomes ake-nisai. Once the second growth season begins, it becomes nisai. In the West, these concepts of time are foreign. As a result, we have come to use the terms in ways that are outside the cultural context.
Query: Is a koi harvested in October as tosai and kept in a dealer's inventory holding tank, such that it does not have the conditions for growth, become nisai when sold in September?
