This page explains in detail the interactions between the Story of Seasons series and the Zelda series.
Harvest Moon DS: Island of Happiness (NTSC/PAL versions)[]
November 12, 2009
Story of Seasons
Zelda
This game features a carpenter character named Gannon, possibly in reference to Ganon from the Zelda series and the way his name was misspelled in the original game. He is a muscular man, and has his lower teeth coming out of his mouth, somewhat like fangs, so there could be a similarity with Ganon.
However, in the original Japanese version, his name was Goran, so given that the name Gannon is not a coincidence, it's safe to say that the reference to the Zelda series was added by the localization team, rather than the creators of the original game, noting a similarity with Ganon (unless the name Goran was based on Goron, but that's a stretch).
Gannon also returns in Harvest Moon DS: Sunshine Islands, since it reuses many elements from this game.
License[]
No specific license was needed for such a small reference, given that it's not a coincidence.