I enjoyed this a lot! The characters and their interactions and relationships were fun, and also had a very interesting sense of underlying tension to them, where things were clearly going well on the whole but they were never purely and uncomplicatedly nice and free-of-stakes; it was very good. (I feel kind of bad for Saori! I hope she and Chisato can keep making progress repairing their relationship as time goes on.) And I enjoyed the period-piece-ness of it; the reminders of what computers and their surrounding culture were like in Ye Olde Dayes were pleasantly nostalgic, and the brief homage to the oldschool NScripter interface was unexpected and delightful.
Also, the portrayal of the creative process itself felt both on-point and... kind of inspirational for me, in my capacity as someone who has an eternal cycle of creative-projects-in-progress none of which ever get finished? I feel like it'd benefit me to pursue a process more resembling Saku and Chisato's process here, with their mix of scoping-down of the project and intense focus on it after determining a reasonable scope. I'm pretty seriously considering trying to spend today on my current creative-project-in-progress, in fact, while this story is still fresh in my memory and thus at its peak of power inspiration-wise!