Monkey D. Luffy

Luffy is generally simple-minded to a fault. Though he has moments of taking things very seriously, such as during fights or intense interpersonal conflicts, he generally approaches most things in a simple, straightforward manner. His simple-minded approach to life has actually saved him against Hancock's powers because he mistook it for a Noro Noro Beam, which was used by Foxy, which brought out a fear of being slowed down (though it is shown later he is simply immune to her powers, because of his pure heart).[86]

Because of his nature, Luffy does not beat around the bush like most people and will often directly call someone out for their personal failings. This usually proves to be beneficial, as he's inspired many people (friends and foes alike) into becoming better, more honest people by simply coming into contact with them. In fact, throughout the manga, Luffy is noted to have little to no thought-bubbles, which the author confirms, stating that Luffy is someone who always says what's on his mind, with virtually no filter.[87] This aspect actually got him into danger one time, when he carelessly admitted to consuming all the oshiruko right in front of Big Mom, just as "O-lin" was depressed after finding an empty pot of it, causing her to attack him. He realized it too late that he declared it out loud, when he actually meant to think it to himself.[88] Luffy often gets quite serious when anyone is in serious danger, notably his crew, whom he considers his family.

If Luffy finds something he does not understand, even if someone explains in detail, he calls it a "mystery thing"; like calling Dance Powder a "mystery powder."[89] One of Luffy's running gags is asking "non-humans" such as the mermaid, Camie,[90] and the skeleton, Brook if they can poop, in which case the answer is usually a yes.[81]

Another running gag is Luffy's slow reaction time to extreme environments, especially to freezing temperatures.[91] It should go without saying that in an actual fight, his reaction time is quite good.

Luffy's simple attitude and naïve comments during fights are often mistaken by his opponents as poking fun at them. Due to this, many of his opponents lose their cool and charge at him in anger. Luffy also has the tendency to unwittingly poke fun at an opponent's most sensitive trait, like calling Buggy "big nose,"[92] Alvida "the fat lady",[27] Kureha "old hag,"[93] and laughing hysterically at Pica's high-pitched voice.[94] In many cases, his opponents fail to understand whether Luffy is serious or just playing around with them during fights due to his sometimes-unorthodox ways of fighting like drinking too much water in his fight with Crocodile,[95] punching out Arlong's teeth and using it as a weapon to bite him[96] or turning his brain off against Enel.[97] Luffy, however, has maintained that he is always serious during fights. In most cases, once he starts to fight, he maintains a serious attitude and is only seen laughing once he defeats the enemy or is certain the enemy will be defeated, like in Buggy's case when he laughed before sending Buggy flying in the air.[98]

He always wears a strawhat from shanks and is kind and funny overall.