This was an amazing concept but I had a lot of trouble understanding the rules, setting it up, and playing the game. Overall I didn't notice many typos in the rulebook, but the wording made it difficult to comprehend and was vague at points. The order that concepts are presented does not seem to be very conducive to understanding, and I had to jump around a lot more than I have had to with other TTRPGs. I'm not sure I can give concrete advice on how to improve the organization of the rulebook, beyond a suggestion to consider how it reads to someone who is completely new to TTRPGs, or at least has only passing familiarity.
Examples of rules and explanations that I could not understand or struggled with:
* Reaction points and perfect points. The use of the word "point" immediately thinks of points as in score, rather than what it refers to in this case, which are the ranges at which reaction and no reaction happens. I think using a word other than "point," along with having explanatory diagrams, would fix this problem.
* The order that reactions happen and are resolved. I'm still not clear on whether the reaction happens fully before the attack that initiated it is finished, for example. The page that explains it also refers to it in terms of player and enemy; I think it would just be easier to refer to the attacking and "defending" party, then the same explanation would apply whether the player or enemy is attacking. This is probably the part of the game I found the hardest to understand, and what I'm still the least clear on.
* The way wide attacks are described: "A Spell Card with Wide 1 will hit the space in front of you, and each space diagonally up and down from you in the same direction." A diagram would have helped, but I think just saying that it's above and below the space in front of you rather than diagonal from you would have made it clearer.
* There's nothing mentioned about what happens when a character gets hit with fling and would go off the edge of the playing field. When I did the Nitori fight I assumed they just stop at the edge of the playing field, without taking damage.
* Movement. The rulebook will say something like "The player can move X spaces..." but what is meant is "up to X spaces." This should be made explicit to avoid confusion.
I think the starter scenario is fine, and the writing for the story there is pretty good, but the boss fights felt kind of unbalanced. They seem to have been designed assuming two players (Aya and Utsuho); I'm not sure if either fight is even possible solo. This could have been improved perhaps by reducing the boss' HP if there's only one player. Even with two players, the bosses are extremely tough; Momiji in particular will just melt the Aya player within a few turns.
The enemies' patterns were confusing to me because they felt too vague to execute deterministically. There are situations where two or more options are possible according to the pattern, and the rulebook doesn't specify a method to use to decide on the enemy's action in that case. I just assumed it was chosen at random. The fights with the regular enemies seemed balanced much better.
I think this is overall a pretty good start for a simple TTRPG, but the rules need to be made more explicit on how various situations as handled, and the rulebook better organized, as well as some balancing done to the starter scenario.