Cat
Befriend Romana. In Fall of Chapter 2, wake up at a later time in the morning than your wife. Romana will knock at your door and give you a cat.

Ducks
First, you must buy a pond for 2,500G from Takakura. Then, during Summer of Chapter 2, wake up in the morning at a later time than your wife.

Goat
Buy it from Van for 4,000G whenever he has his shop open during Spring.

Stop Rain
To stop the rain simply go into the Mine and dig (you dont have to find anything). When you come out the rain will have stopped, this works on Hurricaines too.

Summon your horse from anywhere
Double-tapping R makes your character whistle a different tune, which summons your horse from anywhere in the town.

More Mama's Milk
If you have a milking room, you can push your cows into the room and a machine will milk your cow(s) for you. If you have a cow that produces Mama's Milk push the cow in there. When it's done milking your cow, instead of milking only one Mama's Milk, it will have milked five.

Sleepless Rest
You can get the rest of sleeping without passing any time. Go to the Diary and chose Sleep. It will ask you to Save first. Choose "Yes", and watch the short sleep scene. After doing so, reset the system. Load up your file. It will be right before you went to sleep, but you'll still have the rest.
Pushing
If you are having trouble pushing animals to get them where you want them, close to the bath tub for instance, you have to push them from behind. Then you have to push them from the side to aim them, then push from behind again.

Whistling
If you push in the right trigger (on the top of the controller and not "z") you will whistle for your animals. If you just press it once and you are at your farm, your dog will come to you. If you press it a couple of times, like tapping without letting go, your horse will come to you, and she (assuming that your horse is a girl) doesn't have to be outside.

Selling Items
You can sell items by going to the spot where Van sells stuff. Van will buy anything you have. But make sure you get there before he does or he'll open his shop and you can't sell right then. But remember that you can give discounts to your friends and your girlfriend. And you can sell stuff at night sometimes lots of people come.

Change chicken gender
Note: This trick only works for a hatching chicken. Do not save the game until you get the gender of chicken that you want. After the chick hatches, reset or turn off the Gamecube. The chick might change to male or female. Note: This may require a few attempts.

Quick rest
Select the "Diary" option and choose to go to sleep. Save the game when asked, then reset the Gamecube. Load that saved game file to resume just before the time you went to sleep, but fully rested.

Chase Away Rain and Hurricanes
When it's stormy outside and you want to stop the rain, visit a mine and do some digging. As you emerge from the mine the rain will stop.

Calling horse
Press R(2) to calls you horse from anywhere outside to you.

Change weather
If it is raining or there is a hurricane, enter the mine and dig. After you are done, the rain or hurricane will be over.

Tombstone washer mini-game
In Chapter 2, go to Nina's grave at 6:30 a.m. and talk to Garen. You can play the tombstone washer mini game.

Chinese checkers mini-game
If you enter Kassey's house when one of them is there you can sometimes play a mini game that is similar to Chinese checkers