Wow! What a very normal relationship between two Very Normal People :)
I liked the line early on about how natural agreeing to the confession came; the rest of the game felt like it was responding to that line. How long can you stand to play the role of the 'Love Object' before it starts to wear down on you?
I haven't played the DLC at the time of writing, but I do wish we got to see more of Mafuyu's friends and their thoughts on her. There's attention brought to how Ash overthinks due to knowing how niche and unsettling their interests are, and how that results in their social anxiety. It would have been nice if we had gotten similar insight into Mafuyu herself; I felt like the closest was her saying she had a loving family while also telling her friend that she was getting used to living alone. That seems like a bit of a discrepancy that Mafuyu may not event recognize herself, and could suggest at an underlying loneliness that makes her imprint so hard onto whoever she decides is her object of affection [EDIT: Looking at the comments, and it seems like there might be some side stuff in-game that I missed that might go more into Mafuyu's deal! I'll have to reset and play around with the other options some more....]. Her Yandere moments and how that infects the game was fun though; definitely got vibes of You & Me & Her and DDLC.
Your art is good!!! It's cute style is a nice contrast to the themes and content of the story, and the expressions are great (Ash's eye bags and dead eyed looks are personal favorites of mine)! I always appreciate it when devs make their own artwork while having a clear vision in their head on what they want from their characters. I feel like that results in making something that truly captures their 'voice' better then working with a separate artist would.