Just like Luffy Naruto is fearless and his never giving up nature makes him similar to Monkey D. Luffy.
Edward Elric from Fullmetal alchemist has determination to achieve his goal with the passion similar to Monkey D. Luffy.
Dragon Ball’s Goku has pure heart and loves adventure and always pushes his limit just like Luffy.
Izuku’s journey to become a hero in My Hero Academia is similar to Monkey D. Luffy’s journey to become the pirate King.
Saitama and Luffy have a few common things : fearless attitude and love for thrill of the fight.
Monkey D. Garp is the grandfather of Luffy and just like his grandfather Luffy is fearless and has carefree attitude.
The loyalty towards his friends in Yu Yu Hakusho makes Yusuke similar to Luffy because of his loyalty and love for the friends.