You know what I really loved about the end of Roller coaster ? Is that it doesn't tell you that Loft and Pure end up together because they are soulmates, because that was how it was supposed to be, written in the stars, met when they were five years old and were actually always destined to fall back together and Air was just an accident on Pure's way to her true love.
Roller Coaster shows you that Pure knew true love twice, that Air meant everything, and that now Loft does, and truly it was just a matter of coincidences, of right person right and wrong time, of meeting when you didn't expect it, of trusting luck and choosing what felt right. She could have ended up with Air. Maybe if Air had decided to pick up, decided to come visit the old restaurant they used to love and Loft didn't...Or maybe it would have changed nothing. It doesn't matter. What matters is not fate, it's the choices you make. Loft is the one for Pure, because she's the one she has chosen. Because when they met again, they made the choice of trying again. They chose to trust this love, to make it real, to make it worth it. Nobody is the passive recipient of love. Love is acts, words, choices, thoughts. Perpetually and everyday you make the choice of love and it's true love when you decide it is.
Roller Coaster tells you Pure and Loft ended up together because, even if they didn't have to, even if they could have moved on, and would have still been happy, they chose to.