There is ALOT I love about this story (that bittersweet ending had me in happy/sad tears), but a couple superficial things really stick out for me!
Firstly, The author's depiction of something taboo like menstruation is very tasteful (for want of a better word) and making it a plot point without fetishizing it is incredibly wholesome.
Secondly, I love Remelia's dad, though I don't know why. He had a reaction any dad would have when asked by their young (relatively speaking) daughter about menses/birds and bees, and that was cool.