Demonstrators from various countries across the world have adopted the pirate flag from "One Piece", a popular manga and anime series in Japan, as a symbol for their campaigns. The flag, originally depicting the symbol of a pirate crew in the story, seems to resonate a shared spirit of resilience and defiance against systemic issues.

In Japan, "One Piece" is a much-loved and long-running series that symbolizes camaraderie, justice, and freedom. Its strong themes are often used in discussions and gatherings around societal and political topics. By adopting this flag, it seems that protestors are tapping into this shared cultural linkage to bolster their message.

In the US or EU, using symbols from pop culture during demonstrations is also common, such as adopting V for Vendetta Guy Fawkes masks by the Occupy Movement. What is vital is not where the symbol originates from, but how effectively it communicates the underlying message or feeling of the movement.