A new shop owner named Suitsu opens "Andromeda," stealing all the customers from a traditional dango shop owned by an old man.

This high-stakes psychological battle is widely considered one of the funniest scenes in anime history. 🍥 Episode 66 Summary: Dango Over Flowers

If you are looking for the plot of Episode 66 specifically, it involves a culinary "battle":

Gintama Episode 66, titled does not feature a prominent "paper" theme within the main plot. Instead, the episode focuses on the Yorozuya helping a traditional dango shop compete against a modern, high-tech sweets shop called Andromeda.