One Tree Hill is the story of two half-brothers—Lucas and Nathan Scott. Sharing the same father, the two could not be more dissimilar. What is the only real similarity besides having the same father? Both are talented basketball players. However, Nathan is the star of the high school varsity team, while Lucas is the star of the local playground. Nathan and his father live together, and Nathan is constantly pushed by his dad to always be number one, no matter what the cost to others or himself. This has, of course, lead to Nathan being a spoiled brat, whose relationship with his girlfriend Peyton is predicated on his needs and wishes being the most important part of their relationship.
Lucas on the other hand is very close to his mother, and works in an auto garage with his uncle. He loves to read, but has no steady girlfriend at the time. When his uncle goes to the coach of the basketball team and tells him about Lucas' basketball ability, the coach meets with Lucas to try to convince him to join. After a few attempts, and several confrontations with Nathan, Lucas finally does join the team. This does not sit well with Nathan or Lucas' biological father, who pushes Nathan even harder to deal with Lucas and make sure that his place isn't stolen.
Nathan's position as leader of the team isn't the only thing that Lucas might take, however. Through a series of circumstances, Nathan's girlfriend Peyton and Lucas end up spending time together, and there seems to be an attraction between the two. Peyton is a talented cartoonist, but it takes Lucas submitting her work to a local newspaper for her to get any notoriety. At first upset with Lucas, after a while she begins to enjoy the work she does for the newspaper. Meanwhile, Nathan is having trouble in school, and if he can't get his grades up, he will be kicked off the team. In steps Haley James, Lucas' best friend and the appointed tutor of Nathan. When Nathan first approaches her about the tutoring, she refuses. Later, when Haley finds out that Nathan has gotten the basketball team to haze Lucas to try and force him to quit, she agrees to tutor Nathan as long as the hazing stops. She does not, however, tell Lucas of this. Of course, Lucas does find out, and eventually Haley and Lucas work through things, even when Haley tells Lucas that she is falling for Nathan.
Perhaps Nathan’s biggest obstacle is his father, Dan. Besides being both Nathan and Lucas’ father, Dan Scott, he seems unable to speak to Nathan for even a short period of time without pushing him to do better or reminding him how he needs to improve. Luckily for Nathan, his mother returns and starts to rein Dan in, in an effort to make sure Nathan is not smothered or left totally degraded by his father. Tensions escalate between Nathan’s parents, and when Nathan’s mom decides she wants a divorce, Dan threatens to expose Deb’s own sordid history unless she agrees to let Nathan live with him.
As all good teen dramas go, the four sided relationship could always do with some expanding, and Brooke, another cheerleader decides she would like to try and get Lucas for herself, so she begins her pursuit. When Lucas and Peyton fail to hook up, she puts things into high gear and really goes after Lucas. Eventually, Lucas is forced to make a decision.
The first season ends with several plot lines left dangling. Lucas has made a decision about his life. Also, Haley and Nathan have come to a decision regarding their relationship. Keith decides to try a new start, and both Dan and Whitey are left in medical crises.
