Bill is a character in Harvest Moon GBC 2.
He and his brother Will operate the town's tool shop. As twins, it can be hard to tell them apart. Bill's hair is bright red, while Will's hair is bright green.
Bill will fix your broken hoe and upgrade your sickle. If you bring your broken hoe to Bill, he will fix it and give you the Super Hoe in return. Bill may come to your house on your birthday and offer to upgrade your hoe or sickle as a birthday present. 
Once your barn has four cows, the twins may offer to make you the Cheese and Butter makers. If you have four sheep in your barn, they will instead offer to make you the Yarn and Knitwear machines. Each of these machines will cost 30,000g and will be available for purchase at the tool shop.
"You working the farm today, too?"
"Can you tell us apart? Who am I?"
"We build the computer that's in the library."
"We're thinking of making a time machine next.."
"We guess the time machine's just a dream..."