It's not about "shit fixing itself." It's about using everything in your power to stack the deck in your favour, or to increase the odds of good things happening. Bad things happen; this is a reality. Good things happen; this is also a reality. What happens as a consequence of an action can be dealt with thereafter, as can the consequence of that, and the consequence of that. Each and every one of us is a fractional piece of a picture that is billions of souls wide; what someone does will affect another. Not everyone gets what they want--not everyone can--but it must not stop them from trying. Fight until you win, fight until you lose, fight until you die; run until you can't run, hide until you can't hide, escape until you can't escape. Ask for help, plead for help, beg for help. It's about expending yourself for what you believe in, for what you want, for who you want, and to survive. Sometimes you need a whole lotta luck, and sometimes you don't. What's important is to start heading in that direction. This is the kind of attitude that Hitsugi embodies. It's the kind of attitude that I wish I was strong enough to live every day.
In all of human history, there has been nothing stronger than "an idea." Ideas fuel the engine, and attitudes floor the pedal. For good or ill, everything depended on people using their power to make things happen in order to assert what they believe in. They didn't do it alone; they had so many others to help them in their causes, not to mention luck. Sometimes the change is instant, sometimes it's gradual, but it all depends on people starting it. People fail, people succeed, people continue, people stop and are stopped. Outcomes can't be controlled, but a person's individual input can, and this is the key to Hitsugi's attitude. Put everything you can in trying to do something, and whatever happens afterwards, good or bad or whatever else, will happen. It's as she tells Shizuku after she loses: "Everything over from the beginning."
I don't believe in suspension of disbelief, because I don't believe there's anything in fiction to disbelieve in. As long as it doesn't break the laws of physics (whatever those may be), fiction and reality are entirely interchangeable. There are billions of people alive today, billions of people alive before, and billions of people to come; if it can be thought of, it can happen. It there is a way of acting, it will be acted. If there is a way of being, it will be. All a story is is a happenstance of interesting things, whether that story is "real" or "fiction." All that matters in a story are the ideas and feelings that it gives its audience.
(It's cool, ranting and discussing things are fun)