If you're new at this game, this boss might be a bit annoying. As long as you follow what I say here, all you need to do is memorize his attack patterns. This goes for the rest of the bosses in the game too!
Ok the boss of this shrine is a really goofy-looking mole man in a one piece swim suit. When I say this guy is goofy-looking, I mean it.
Before you face this guy you need to get some equipment on. If you followed my easy money submission, go to the Gemini General store and buy the following items: Straw Hat, Neck Scarf and Iron Bracelets. Next, go to Daedalus Blacksmith and buy a Fire Rod. Whatever weapon(s) you have besides the Fire Rod, put them in your trunk and ONLY keep the Fire Rod for this fight. This is a boss you DO NOT want to get in close to.
Go to the top floor and face this......thing.
The Fire Rod will only whittle his health down, like they say, slow and steady wins the race.
There is one move he uses you MUST avoid AT ALL COSTS. He will twist his body as if he's about to spin like a top (and he does). When he does this move, GET THE HELL AWAY FROM HIM and run around the arena until he stops and staggers around, clearly dizzy. Then proceed to continue hitting him with the Fire Rod until he's toast (pun intended).
As I said, if you're new to this game, it might take you a couple of tries but don't get flustered. Just watch for the curling motion he does before his spin attack and you SHOULD be fine.