He was depicted as a kind, well-mannered and friendly young man who is quite popular. He got along well with both Lilo and Stitch and enjoyed their company, being one of Lilo's few human friends. He is slightly eccentric, as he considered Pleakley pretty and had a crush on him, but Keoni did get over it within a week. He is patient and understanding, offering to teach Lilo how to skate in "Kixx", and telling her that it took time and patience to learn to skate. He is a calm, easygoing individual and seems somewhat aware of Lilo's crush on him, but doesn't seem to mind as shown in "Nosy". In "Melty", when Lilo did a luau with mud as an excuse of why she was in a mud pudle, he was kind enough to give her a mud monster doll, saying the luau seemed cool, showing he is supportive and nice. He seems athletic and enjoys skateboarding, as shown in "Kixx" and "Morpholomew", and plays basketball in "Splodyhead".
Lilo constantly tries to vie for Keoni's affections. He had a crush on Pleakley, whom he knows as Lilo's "aunt," in the episode "Hunkahunka" (where Lilo tried to use a hummingbird/love potion experiment to make him fall in love with her), but in "Nosy", he stated that he only had the crush for that one week. In "Nosy", Nani invited Mr. Jameson and Keoni to her home to show her family's spirit of hospitality, in order to get the job she desires. Lilo tries her best to hide her crush on Keoni, a task that proved difficult due to Experiment 199 (Nosy) who likes digging up secrets. His father owns several businesses on Kauai, particularly a famous hotel. He has another female friend named Sara, who always thinks she's his girlfriend, despite Keoni telling her repeatedly that he only likes her as a friend. This friend is also later seen in "Morpholomew", competing in a skateboard competition. He keeps Experiment 202 (Jam) as a pet.
In "Splodyhead", Keoni was seen playing basketball with a female friend before Stitch, riding on a tricycle with Lilo, interrupts and catches the ball in his mouth before spitting it into the basket, and he and his friend run when Gantu comes.
In "Sinker", Lilo was helping Keoni prepare for the boat race, with the motive being that if she helped she believed he would give her a free boat ride. She notices Sinker in the water and warns Keoni in time ot jump off the boat to safety on the shore. Unfortunately, his boat is wrecked in the process. Lilo later gives him a cruise liner for the boat race, much to his dumbfoundment.
In "Kixx", Keoni showed off his skating skills and offered Lilo a try. She fell and claimed the board was defective. He was later surprised and a little annoyed when Stitch went through his backpack and threw out all of his stuff except his left shoe and macadamia nuts, both of which Stitch ate. When he sees Lilo trying to ride a skateboard again, he stops her and tells her he won't let her go until he teaches her how to ride properly. She manages to learn due to his excellent teaching.
In "Melty" Lilo fell into a mud puddle while Stitch was chasing after Melty, and Keoni asked if she was all right. Embarrassed, she said she was doing a luau on a mud monster and he leaves. She decides to use Jumba's time traveling surf board to go back in time and redo the incident to make sure she didn't fall in the mud puddle, but each time it messes with the time stream and makes things worse. She decides to redo the incident to correct the time stream but feels embarassed. However, Keoni goes over to her house and gives her a mud monster doll, complimenting her on her luau, much to her happiness and surprise.
Nani mentions Keoni in "Wishy-Washy" as Lilo's crush, but she denies it as she is pretending to have a crush on a different boy to see what Nani's type is in order to find a way to improve David to make him more likable to her.