Twinleaf Town is the player's home town in Pokémon Diamond and Pearl and Pokémon Platinum. This is the first time that there is not a Pokémon Lab in a starting town. It has four houses, the house in the bottom right hand corner is the player's house. The house in the upper left hand corner is the rival's house. Twinleaf Town also has a small lake at the very bottom. (Later when you get the HM move "Surf" you will be able to get an Odd Keystone at the small lake if you surf until you get to the mid part of where the trees are, press A and you will get an Odd Keystone.)
"You have just watched a show on the Red Gyarados." Head downstairs and your Mom will tell you that your rival is looking for you. She also warns you not to go into the tall grass. Now head outside and go to the north west (top left) house, your rival's house.
Blocked Route 201
You cannot access to Route 201 unless you have spoken to your rival.
Meet Your Buddy
Head to your friend house located at northwest of Twinleaf Town. When you reach the entrance, your friend will knocked into you. Then he went off and went back again to take the things he forgotten. You enter the house and go upstairs, you will see him packing his things. He will then run downstairs again. Meet him at Route 201.
After battling Pokémon and meeting Professor Rowan and his grandchild, you will return home. Upon arriving home, your mother tells you to meet Professor Rowan at Sandgem Town, and she gives you the Running Shoes. Now head to Route 201 and began your journey to Sandgem Town!
After Visiting Sandgem Town
Head home to tell your Mom about the big quest you are going to embark on. After telling your Mom about the quest you will be taking she gives you a Journal to record things that happen to you along the way. Right after you receive the Journal from your Mom, your rival's mother will enter. She forcefully asks you to take a left behind parcel to your rival. Head to Jubilife City to give your rival the parcel.