A Marshgreen tale tells about how the island's mountain, Mount Frigid, once fell cold and was abandoned by its inhabitants. Why this happened is unknown, but maybe a clue lies in the mountain's strange pull on the island's most mysterious child, Feather.
You can read the chapter HERE

The Forgotten Mount Frigid is a two-part short story about young Feather's trek up to the top of Mount Frigid after giving in to a strange "pull" that he had been feeling from the mountain for a while. He wanted answers, especially about what had happened on the day of the Piranha Plant attack when he sprouted wings while running away.
This short story won't be necessary to understand the plot of Fish Scales. It just elaborates on something that will get brought up in the next Fish Scales chapter that I wanted to expand on but couldn't easily do from Itsuki's point of view.

Every chapter of Fish Scales is available to read here