Three kids, two boys and one girl, are left alone on a tropical island with no other human contact. I'm not surprised the two boys would compete for the girl’s heart, but right from the beginning of the original Kingdom Hearts, I can see it between Sora and Riku. Riku even tells Sora that if he doesn’t share the paopu fruit with Kairi soon, Riku will. Oh SNAP, THINGS JUST GOT REAL. SCHOOLYARD JUSTICE, SON.
When the three get separated, Sora saves Kairi while Riku allows the darkness to overcome him, becoming a major nemesis for the heroes of light. Riku leads Princess Jasmine to Maleficent, kidnaps Pinocchio, and allows Ansem to possess him with the promise of more power. Eventually, Riku comes to his senses and helps Sora, and he’s been helping him ever since, but for a while he was a real jerk. You’re never going to win Kairi’s heart by dabbling in darkness and letting Sora save her. Come on man.