It has some learning because you learn how to take care of animals this way. You can also get married.
Boys can marry:
Felicity, Iroha, Yuri, Tina, Michelle or The Witch Princess.
Girls can marry:
Neil, Allen, Rod, Soseki, Sanjay and Amir.
I'm currently married to Neil and expecting a child. Once you get married you build the child's bed and you trigger the pregnancy event. Eventually you give birth. The child goes through stages: Baby, Crawler, Child and Temporary Teenager. However, there are some sad parts.
Your boyfriend/girlfriend may break up with you, and this triggers the breakup scene.
The farm animals you raise may die in the morning when you make up. Very sad music plays when this happened. In Harvest moon Grand bazzar, when this happened to my chicken, I CRIED. However, if you have a high bond with them or if you save before the death, it may survive the next morning.
Animals can get stressed out if you hit them with tools, neglect them, or leave them out in snow storms, tycoons or rain. Once stress builds up you must give them medicine, or the death scene will trigger and they die.
Pets (Cats, dogs horses) live forever I guess: They only get fat when stressed out.