No, they're not the same. Story of Seasons is a new series that developed from the Harvest Moon franchise but has some distinct features and gameplay differences.
They aren't identical. Harvest Moon was the original, and Story of Seasons is a continuation with its own tweaks and improvements. The worlds, quests, and overall feel can vary between the two.
Harvest Moon Love Story's plot is centered around the idea of love in a rural, farming - centered world. The player's character arrives at a new place and is immersed in the local community. As for the love story part, it's about exploring feelings and connections. There are different characters with unique personalities. You have to work on your farm, but also make time for socializing. The love aspect could start with a simple friendship and then evolve into something deeper. You might face challenges in the relationship, like misunderstandings or competition from other characters, which all add to the richness of the love story.
Well, growth is a common theme. The main characters usually grow as individuals, learning new farming techniques or becoming more responsible. Family is also often a theme, whether it's about starting a new family or dealing with family members in the village. And nature is a theme too, with descriptions of the beautiful landscapes and how they impact farming.