This formal looking fellow uses flowers and scented oils to create perfumes. He doesn't have a shop where you can buy his creations, as he seems to prefer researching new scents rather than selling the perfumes for profit. He isn't just searching for scents that smell nice, but scents that invigorate or have other affects when used.
Klaus has lived in Oak Tree Town for a long time, and you'll meet him from the start of your farming adventure. His house is in the western side of town. Klaus does his scent research inside his house, so while he is working you won't be able to give him a gift. This will typically be Sundays through Thursdays from 8am to 10am, and again from 19:30 to 22:00. On Sundays and Wednesdays he'll be out of town between 11:30 and 18:00.