Watashi no Pony
This game is titled Pony Friends in North America, Europe, and Australia, and Watashi no Pony in Japan.
Picture set prize
When you finish a picture set of four animals in your journal, you will get a prize of an accessory or coins; likewise for coins and shells.
Complete your chores for coins.
Winning Pony Club races
During a Pony Club race, shout into the microphone, but do not shout so loud that the meter goes into the red. This will slow down your pony.
Go for a ride in Sandyfoot Valley. Get your horse to gallop and you should see a grey squirrel jump out of a wall. Note: This might not work every time.
Strategy guides from GameFAQs