Summary:
- The article reports that the video game "One Piece Pirate Warriors 4" has surpassed 4 million units sold worldwide.
- The game is part of the "One Piece Pirate Warriors" series, which is based on the popular anime and manga series "One Piece".
- The game's success highlights the continued popularity of the "One Piece" franchise and the demand for video game adaptations of popular anime/manga properties.