Koopa Koot's favors

In Paper Mario, the elderly Koopa Koot of Koopa Village will ask Mario many favors throughout the game. Some of the favors require Mario to meet specific people and get an item in return. On 5 occasions, Koopa Koot will give Mario Star Pieces, making this sidequest a necessity to complete the game 100%.

When Kooper joins Mario's party
Koopa Legends: Koopa Koot wants to read the book Koopa Legends, and Kolorado is the only person with a copy. Head a few doors down from Koopa Koot's house to Kolorado's house and ask Kolorado's Wife for it.

- Reward: One Coin

Sleepy Sheep: Koopa Koot has been having trouble sleeping lately and wants a Sleepy Sheep to make him sleep better. Give him one from the shop in Toad Town, there is also one of these items in Pleasant Path.

- Reward: One Coin and the Silver Credit

After Chapter 1
Tape: A long time ago, Koopa Koot loaned Goompa a Tape. Now he wants it back. Just go ask Goompa in Goomba Village about it and he'll retrieve it.

- Reward: One Coin

Koopa Tea: Koopa Koot wants some of Tayce T's famous Koopa Tea. Take a Koopa Leaf from a nearby bush and take it to her. She'll brew a cup to return to Koopa Koot.

- Reward: 3 Star Pieces

Luigi's Autograph: Koopa Koot's a big fan of high-jumping Luigi. Catch him wandering around outside Mario's house and ask him for it.

- Reward: One Coin

After Chapter 2
Wallet: Koopa Koot's lost his Empty Wallet. Try checking Koopa Village's bushes.

- Reward: One Coin

Tasty Tonic: The old Koopa wants another treat - this time, it's a Tasty Tonic. Shell out five coins for one in the Shop in Toad Town.

- Reward: One Coin

Merluvlee's Autograph: Adding to his autograph collection, Koopa Koot wants Merluvlee's. Visit her in Shooting Star Summit and she'll ask for a Crystal Ball from her sister, Merlee. Head to Dry Dry Outpost and speak with her. Bring the Crystal Ball to Merluvlee, then bring the Autograph to Koopa Koot.

- Reward: 3 Star Pieces

After Chapter 3
Toad Town News: Koopa Koot's always at a loss for the goings-on in the Mushroom Kingdom. Go to Toad Town and read the front and back of the sign near Merlon's house. Head back to Koopa Koot.

- Reward: One Coin

Life Shroom: Koopa Koot is feeling his age and wants a Life Shroom in case something happens. Buy one in Boo's Mansion for him.

- Reward: One Coin and the Gold Credit

Nutty Cake: Next on the list of gourmet recipes for Koopa Koot is the Nutty Cake. Whack a Goomnut from the tree in Goomba Village, then take it to Tayce T. Give the resulting Nutty Cake to Koopa Koot.

- Reward: One Coin

After Chapter 4
Quiet Down!: Those nasty exploding Bob-ombs next door are giving Koopa Koot a migraine. Speak to them with Bombette active. Apparently something of a sappy heartbreak story will ensue. Hold back the tears and return to Koopa Koot for a gracious reward.

- Reward: 3 Star Pieces

Old Photo: Koopa Koot wishes to reminisce about the old days when he made friends with the Boos in Boo's Mansion. Ask the very first Boo upon entering the mansion and he'll give it to Mario.

- Reward: One Coin

Koopasta: Koopa Koot is desperate for some Koopasta. Grab a Koopa Leaf nearby, then head to Dry Dry Outpost for some Dried Pasta. Take both to Tayce T. for some Koopasta. Then give Koopa Koot his dinner.

- Reward: One Coin

After Chapter 5
Glasses: The increasingly forgetful Koopa Koot has lost his glasses. Once again, check all the bushes in Koopa Village until they turn up.

- Reward: One Coin

Lime: No cooking necessary for this one. Travel to the Oasis in Dry Dry Desert and hit a tree for a Lime. Take the tart treat to the tiresome turtle.

- Reward: 3 Star Pieces

Kooky Cookie: Koopa Koot's heard the word about this sweet treat. Grab a Koopa Leaf, then head to Shy Guy's Toy Box and battle a Shy Guy for a bag of Cake Mix. Tayce T. will combine them to make a Kooky Cookie for kooky old Koopa Koot.

- Reward: One Coin

After Chapter 6
Package: For the next game of fetch, head over to Gusty Gulch and talk to the Boo near the Save Block. Leave the screen, then come back, and the Boo will hand over a package. Deliver it to Koopa Koot.

- Reward: One Coin

Coconut: Koopa Koot wants to see a Coconut before he dies. Set sail for Lavalava Island and smack one off the trees near or in Yoshi's Village.

- Reward: One Coin

Red Jar: For Koopa Koot's final errand, he wants a Red Jar given out at Little Mouser's Shop in Dry Dry Outpost. Traipse on over there and buy the following items in order: Dusty Hammer, Dried Pasta, Dusty Hammer, Dried Shroom. Little Mouser gets the hint and promptly hands it over.

- Reward: 3 Star Pieces

Trivia
The concept of Mario doing favors and running errands for people would be recycled in Paper Mario: The Thousand-Year Door with the inclusion of the Trouble Center.