Dirk is a secret eligible marriage candidate in Harvest Moon: The Tale of Two Towns.
He is the mailman between the two towns. Everyday he travels from town to town, so he can be a bit hard to track if you don't know his schedule. He delivers the mail everyday except Sunday, full-rain days and stormy days.
To unlock Dirk, be in Summer 1st, Year 1 or later. Walk from Konohana Low-Mountain area to the Konohana entrance area between 9:00 am to 8:00 pm on a sunny, snowy, or half-rain day. If you are riding your horse, the event will NOT trigger however it doesn't make any difference what town you live in.