The marriage proposal surprised me (in a good way), but let's calm down. Aya has to respond to the proposal, and maybe it wouldn't be a bad idea if she said “Not yet.” That would give them both time to work on communicating with each other, reflect on the mistakes they've made, and deepen their relationship.This would help them gain maturity and confidence, and their relationship would become much stronger. They would then be much better prepared to face life together without doubts, a lack of communication, or fear causing their bond to crumble like a house of cards.
(I let out a "SQUEEEEEE!!!!" on the last page, so I'm the first one who needs to calm down)