You have really helped me see a lot of the flaws I had!
—SPOILER WARNING FOR ANYONE WHO HAS NOT COMPLETED CHAPTER ONE—
Speaking of Zinnia... she definitely will not be a romantic interest. For starters, even Sora does not really have any romantic interests himself. So, even though I know some people will not be happy about this… I still want to do it my way: Sora will not the only male character. I want some of the female characters to have the chance to meet —and maybe fall in love with— other side characters.
Sora mainly serves as a bridge for Zinnia to start interacting with other inmates, since he already knows the girls within the group. But I will also be introducing entirely new inmates as well!
About "that" character's death… well, as Sora mentions, it was not really her death that made Zinnia sad. It was more of a wake-up call that pushed her to stop running and masking her reality with weird humor and sarcasm.
And you are absolutely right about Charly. Especially in Chapter 2, I feel like her potential was somewhat wasted (with that introduction in chapter one) because of all the controversy she will stir up. I will work on finding better ways to present characters, either by showing rather than telling, or letting them speak for themselves without relying too much on dialogue!
Thank you so much for taking the time to share your thoughts. And sorry it took me a while to respond properly. I really appreciate your feedback!
EDIT after three months:
I will be working on changing certain aspects of the game to make it feel more like a harem rather than NTR, and I've received some great ideas to help with that. Sora will now be more open to romantic encounters with the girls he meets, and they'll be more responsive in return.
Now that Zinnia is officially part of the roster and is 18 years old, she can potentially become a romance option as well.
Thank you all so much for your feedback and for helping me strengthen my weak points. It's been incredibly helpful!