When Lana and Ash came fishing, he informed them that they needed his permission to fish. He agreed to let them fish if they managed to find a Feebas, which Lana, to his astonishment, reeled in almost immediately. He then told the duo that they'd need a boat to fish, and said that they could borrow his boat if they gave him the Feebas, which they agreed to. He also stayed on the site to observe how Lana found, fought, and eventually defeated the Totem Pokémon.
The master fisherman likes to recount tales of how he has tried to reel in the Totem of Brooklet Hill, although his stories seem highly exaggerated, as he tends to add decades into the time he has spent doing so. He also wears fake scars on his arms to show off as "proof" of his battles with the Totem.
Feebas was a Pokémon that Lana reeled in at Brooklet Hill. She gave it to the master fisherman in order to use his boat.