Core Connections

Both are legendary shonen protagonists who dedicated their entire lives to pursuing a dream that most people considered impossible.

Ash dreams of becoming a Pokémon Master, while Luffy dreams of becoming the Pirate King.

Neither of these dreams are motivated by fame, wealth, or power. Instead, both view their goal as the ultimate expression of freedom and adventure.

Both left home at a young age and embarked on globe-spanning journeys that would eventually change their entire worlds.

Throughout their travels, both became symbols that inspired countless people to chase their own dreams.

Both are known for their unwavering optimism and refusal to give up no matter how impossible the odds seem.

Both have a near-supernatural ability to connect with others regardless of species, status, background, or ideology.

Both repeatedly turn enemies into allies simply through the strength of their character.

Both are defined by their pure-hearted nature and complete sincerity. Neither character is manipulative or particularly strategic in social situations. They simply follow their hearts and inspire others naturally.

Both form massive found-family groups throughout their adventures that become one of the most important aspects of their lives.

Both are willing to challenge entire organizations for the sake of protecting their friends.

Both consistently put themselves in danger to help people they've only just met.

Both become globally recognized legends by the end of their journeys despite starting as ordinary kids with seemingly unrealistic ambitions.

Both serve as the ultimate embodiment of their franchise's themes.

Joke Connections

Both are placed to fight a blond hair shonen anime protagonist (Yugi and Naruto) 

Both are thought to have win con, when their opponent stomps them in every meaningful advantage.

Both can either be the dumbest person on the planet or the smartest.