Her former companion likes sour grapes... She found a magic to make sweet grapes sour (last chapter)... This detail made me so emotional ;A; What's with this manga :'D
Oh, damn, the grapes line actually did make me cry. First time I've cried reading this, but definitely not the first time I've felt like doing so here.
Yeah, that explains the grape spell.
So a year passed for no greater reason than giving the human girl a birthday, remarking on her height and taking note of her having tits.
Is the hero her unrequited love? Kinda seems that way, Because of his species short life span she decided to not get too attached to him but seeing how she keeps reminding herself of the hero still....it truly would've been beyond painful if she did progress her relationship in that direction.