Maybe I don't get what you're trying to do here, but I'm finding it very confusing.

I like leading with the characters.

Why does the bit following that, "Playing the Game" talk about "play", "storylines", "scenes" and then the "deck", when we don't even know what we're doing here or why? If you're talking about playing the game, why not tell people how to actually play?

On page 11 you say "before you start play proper", but I don't understand what that is.  Is there a reason you don't explain what "play proper" is?

Have you thought about presenting the rules more procedurally? i.e. tell people what to do from the moment they sit down at the table.  In that case, I'd present the rules something like:

How many players?

Choose a character

Setting up a scene

Threats

Deal Cards (and describe what they're for)

Playing a scene

Rules for cards

Ending Scenes

A New Storyline

Does that make sense? It's not super different from what you have now, but I felt like you were trying to describe play without telling people how to play.

On that note, you don't give any advice on what players are trying to achieve when they play.  If I play a card, why do I do that? Because the rules tell me to, or because it lets me do something I want to? Maybe you've left this deliberately vague?

Hopefully that's useful.  I feel like maybe I'm fundamentally misunderstanding something about your text?

The Japanese says "boizu rabu no TRPG" (The Boy's Love RPG). It's basically a translation of the english subtitle.

You have good stuff. FYI, nothing is being left deliberately vague. Anything vague is accidentally vague. I don't think you're misunderstanding anything.