Nana and Muna are two cats who lived peacefully in the cat kingdom — until a great flood struck without warning and changed everything. Stranded on a remote island, they have to build a new life from what they can find around them. Repair the broken bridges, construct houses, and farm the land. The island holds traces of something older: ruins, unexplained structures, beautiful gardens, a castle with no apparent owner. Secrets are here. So is the ocean, which can be navigated by boat — and beyond it, an expansive world worth exploring.