It's a pretty straightforward theme about how an animator visiting her childhood muse to escape from writers block?
It's not a complex theme but it's honestly a common feeling for creators. When you get stuck you daydream about what you found fun in your childhood.
Unlike a lot of other anime about being a loser who does nothing, Zenshu is actually a decent mindset for a go getter animator. We all get stuck and sometimes overworked. But we can often find inspiration from our childhood memories.
