Basically a love story, where at first the girl has no real interest in liking anyone, she basically just wanted a change in her life. However the two boys she decides upon in a game of "swim competition" she chooses one over the other to take out on a date to see fireworks.
Through fate, the bead the girl found early on in the movie gets into the hands of the boy that lost the swim race that day. By accident invoking some power in this bead, it reverts time a few hours back AND alters the reality he is living, changing the outcome of the swim competition into his favor.
Over time the boy realizes its effect and keeps using it to alter the world around him to his favor, to where she will eventually actually like him. When she finally does fall in love with him, the multiple words disappear and the two go off to together "doing stuff". (At the point she falls in love with him and he shows he loves her, the orb shatters and shows to him and her "possible futures" with one another, like traveling the world etc)