Kawa no Nushi Tsuri 5: Fushigi no Mori Kawa

In this game, the player's father takes them on a fishing trip out in the country. After being pulled into the water, they end up in a strange realm where the people have been cursed and turned into fish. The player must save the people and undo the transformation by catching them. This time around, battles are fought with the fish themselves rather than random encounters.