Kouta, the protagonist, runs a fishing business and operates a boat inn called “Ootaki.”
Returning from a routine fishing trip, he notices two sisters who’ve apparently come from the mainland.
A misunderstanding leads to the older sister confronting him—turns out, these two are the daughters of the Natsume Group, the owners of the island Kouta lives on.
They’re looking for the Ootaki boat inn.
Even if the girl was unpleasant, Kouta couldn’t just send them back after they’d come all the way from the mainland. They might be customers, and business was business.
So, Kouta leads the two sisters to Ootaki.
This terrible first meeting with Ruka and Mafuyu turned out to be the start of something that would change his perspective...

[Translated from the official website]