It’s different now - they’re different now - especially in contrast to who they were before Heartless and Keyblades and journeying to those other worlds they had speculated upon. Three hearts, all entwined; darkness and light and love. Fingers lock hands together, no longer caring who should hold whose.
They three are all older now. A little more grown-up, a little more knowledgeable, a lot more mature. But there are still a few more years before they are to become adults and they revel in that.
The smooth, wet sand is interrupted by erratic footprints; deep and shallow and twisting, telling a tale only to slowly be erased by waves lapping about the shoreline. Two not-quite-boys, not-quite-men dance with blades and without; sweat and sea spray and sand coating their mostly bare skin. Their only observer in the slowly dwindling daylight sits a ways away, feet digging restlessly into the warm, dry sand.
Kairi watches as they weave to-and-fro around one another, grasping and touching and not quite keeping hold. It is sparring, it is playtime, it is Riku-and-Sora. And she is merely waiting for the most opportune moment to get the jump on both of her boys at once.