A simply pleasant and stirring experience, this is a gorgeous debut in every sense of the word.
The art is gorgeous and intimate, the music is appropriately emotional when need be, the story itself is just so grounded and filled with natural interactions, I would often find myself forgetting this was a Touhou story of all things. The choice of characters, as others have said, is inspired. I hate grouping characters into "smaller" and "larger", but we really don't get to see a lot of these three, so getting to know them so deeply here is a wonderful touch which lends the project even more uniqueness than it already has.
I found myself sympathetic and understanding to Kutaka's internal and external plights, and to Kyokou's sense of apprehension and nerves for being out of her element; their concerns are just so innately real, it hurts to read at points.
The art, as said before, is gorgeous. The hand-drawn style really sticks out to the eye and the small animations really do make a world of difference; Kutaka being able to fly away, Mystia leaning into tease Kyukou, Kyukou taking the first step... all of it is made real and lends that much more impact to what's happening. And that's not even getting into some of the other stuff. The UI is drop-dead, and the inserts add so much character to an already unbelievably rich tapestry.
The music was so nice too; it lent to an atmosphere of curiosity, anxiety, and earnestness which highlighted the action with wonderful accuracy.
The extra notes unlocked at the end were also wonderful; I wish we could get more of that sort of thing with these sorts of projects. It gives this project an even more heart-felt feel.
I am genuinely in awe, and would love to pick your brain on the more technical stuff behind this project in the hopes I can find some future inspiration.
Well done, team. I look eagerly to your next project together.