It's basic for now, but I see some potential. I love the idea of how it's going to evolve between the hero and the demoness, even if I find it quite fast for the spicy stuff.
my ideas for the future:
during battles and discutions, the sprites are too tiny compared to the room they have on the screen.
My suggestion :
during discussions, you could play it like a visual novel (you can keep the letter style to show the text but the caracters shoul use more space on the sides), and during battles, I think you could improve the look. either you could show both the team and the ennemy, or just the ennemi, but you should use the screen's space properly
if the game is more story focused, I think you should avoid mob maratons and focus on the scénario so we have a better view of what the game is about.
little bonus for one that could be hard to pull of, but it could be cool if battles where more scenaristic than turn based. and so we could see the real alchemi between the hero and the deviless. and there, your choices during battles will have more impacts on the scenario (I tried it myself and It's great for immersion, but that asks quite a lot of work for eatch so it will be more about quility than quantity. I can give you more details if you are intrested.)
just personnal taste, but I don't really like the "you" format on story based story. If I can compare myself in the hero, that's a plus. But in a story, I prefer reading the stories about someone else rather than pretending it's me.
That's all I have to share right now but I'm quite eager to see where it will go.
really promising