She's never bothered with her imagination. Things are real. If they aren't real, then they aren't worth bothering about.
Tatsuki's world is very straightforward. So Orihime can shoot flower fairies out of her hair? Good for Orihime.
If there's a giant squamous monster sitting on top of the school, then only idiots stand round wondering if it's real or not.
Sensible people start considering where to kick it.
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