It's good to carpool with your friends.
Kai has a car and goes to high school, but doesn't have a job or a lot of money.
Kai wants to travel by car to school.
Kai talks with his friends and offers to drive them to school if they help pay for gas.
Kai figures that the privilege is worth it and drives himself to school despite the cost.
Kai's friends enjoy the rides to school and Kai has enough money to do other things.
Kai doesn't have a lot of money to use for other things, such as outings with his friends.