Ume is Lost

The son, Kokari, is fishing along the banks of the great abyss.  Kokari was worried about the bridge project and so he and his dog explored the Tsuta Ruins.  The dog got trapped inside and the key to the ruins fell into the great abyss.  Note the lack of responsibility.  Did I mention that Kokari is also a total brat?
Issun lectures the kid about his inaction to fix what he broke.  Speaking for us, Issun says will not be there to solve the problems for the kid (which is a first considering that we have been micromanaging every personal problem in greater the Nippon region).  

However, we decide to help the kid find his dog by unearthing the key to the ruins.  You once again control every aspect of the kid catching the fish.  Follow Issun’s fishing steps to catch two fish.  The third one will be the great salmon.  When caught, the salmon vomits the ruins key.  Kokari really wants it, but silly rabbit-head, ruin keys are for gods.  

Use the bite button to take the key over to the ruins, which are circled on your map.  If you drop the key, the kid will steal it and you will have to return to deep abyss and head butt him to get it back.