Quick answer
Nautical charts are used to locate remote islands where players can hunt for treasure and befriend rare animals.
Confirmed details
- The charts reveal island locations.
- Some island animals are not found on the mainland.
- Remote islands support treasure hunting.
What this means for players
Chart names, acquisition methods, island count, travel steps, and individual rewards remain unpublished.
This answer is intentionally limited to the current game’s published information. It does not import values, characters, schedules, or mechanics from earlier Harvest Moon titles.
Official source
Natsume title announcement — March 11, 2026. Independently summarized and checked on 2026-07-19.