Heterogenia Linguistico manga volume 5 features story and art by Salt Seno.

As spring finally arrives, Hakaba’s party finally finishes their journey to the coast. As they begin their research on the new region, Hakaba is swept into an underwater cave by its residents—who are indistinguishable from fish! Will Hakaba be able to figure out how to communicate with the inhabitants and escape from the cave before it’s too late?