The Legend of Zelda: The Wind Waker/Side-quests

Killer Bee Gang
In the plaza on top of Windfall Island there is a school called Mrs. Marie's School of Joy. If you go talk to the teacher inside she'll tell you about a gang of four boys who never listen to her. She asks you to catch their leader, a boy named Ivan, to talk some sense into him.

Outside the school there is a gang of four boys walking around. If you go talk to them and speak with the boy in the hat he'll tell you the gangs name is the Killer Bees. He'll challenge you to a competition of hide and seek. He explains the rules how they won't hide indoors and they won't leave the island. If you find them they will run and you have to catch them. You have to catch all four of them.

After the boys scatter head through the archway to the left of Mrs. Marie's School and turn left. The first boy is behind the bush. Once you get close enough he'll take off running. Run after him and all you have to do to catch him is touch him.

Next head over to where Tott is dancing in front of the shrine. Behind the stone is the second boy. Catch him when he runs.

Next head over to the Southwest corner of the island to the bomb shop. If you walk to the left side of the building you can sidle across the ledge and get to the back of the shop. The third boy is hiding there. Chase him down when he runs.

The last boy Ivan is on top of the tree nearest to the mailbox. Roll into the tree and you'll knock him out of the tree. After you chase him down they will reward you with a piece of heart.

They will then ask you to apologize to Mrs. Marie for them and when you do she'll reward you with 50 rupees. When you walk back outside the Killer Bees will tell you it's Mrs. Marie's birthday soon and that she likes Joy Pendants. Head down to the bomb shop and roll into the tree that is by the front door and a Joy Pendant will fall out.

The Killer Bees will ask you if you can give the pendant to Mrs. Marie. Head back up to the school, equip the Joy Pendant and show it to Mrs. Marie. She then tells you she'd be really happy if she had 20 Joy Pendants and rewards you with 20 rupees. Once you give her 20 Joy Pendants she will reward you with the Cabana Deed. Once you receive it, you will be able to go into the house on Link's Oasis. Once you give Ms. Marie 40 Joy Pendants she will give you the Hero's Charm, which is a mask that allows you to see the health bars of enemies when you are locked onto them.

Huricane Spin
To unlock a special attack called the Hurricane Spin you must gather 10 Knight's Crests. The best way to look for them is to deafeat a lot of darknuts; you can even see them wearing it, or you can find some in chests. After you have gathered enough pay Orca a visit. Go to the back of his house where you will see a Knight's Crest on a shelf. Check it and show Orca your 10 Knight's Crests. He will stat rambling about his past and then teach you the Hurricane Spin. Yippee! Be be carful though it costs magic.