I'm sure Makoto's little kiss on Hikari's cheek helped. I say it's fine that it wasn't even a kiss on the lips. His goal was to distract her from the emotional discomfort of seeing her ex again (who's with another girl at that), and it ended up doing just that, giving her the emotional support she needed right at that moment.
Her ex clearly doesn't love her anymore, but there's someone already there in front of her, ready to love her, and it's someone she's already started to have feelings for. It's no longer about the past, but the present.
It's finally over. So they decided to wait while keeping their feelings for each other alive. No official dating, no romantic kisses... yet. This is one ending to a romance I can actually forgive without seeing a romantic kiss on the lips or the couple to start dating officially. Their circumstances are understandable, but at least their feelings are true, mutual and known to each other (well, I think Makoto got the message when Hikari said "before we start going out").
It's just a matter of patience... a lot can happen in ~3 years and if their feelings survive that long they deserve to go official.
This has been clearly axed, but let me dream about the possibility of a sequel set after a time skip...