One Piece: Umi no Heso no Daibouken-hen

The Straw Hats encounter a city in the middle of a whirlpool, called the Ocean's Navel, that is being destroyed by giant monsters. These monsters supposedly protect a treasure capable of granting wishes, but in the process of defeating these guardians, the crew ends up releasing another evil.  (aired after Episode 53)
(Source: Wikipedia)

Name: Monkey D. Luffy Age: 17; 19 Birthdate: May 5, Taurus Height: 172 cm; 174 cm Blood Type: F Affiliation: Straw Hat Pirates Position: Captain Devil Fruit: Gomu Gomu no Mi (Gum Gum Fruit) Type: Paramecia Bounty:500,000,000 (previously; 30,000,000, 100,000,000, 300,000,000, and 400,000,000)  Luffy is the captain of the Straw Hat Pirates and is best friends with all of them and values them over all else. At first glance, Luffy does not appear to be very intelligent, often seeing things in childish manner and can easily be amazed by the simplest things. However, because he views the world in a straightforward and simple manner, he is occasionally the only person who can see past the events and see what should be done.   Luffy seems to have an unstoppable appetite, a characteristic that is common to the Japanese archetype of the (at times simple-minded) young male hero/adventurer with a heart of gold; perhaps the hunger more so in Luffy's case due to having an elastic stomach. Luffy is also another one of the several characters given the middle initial "D."  Although Luffy is fairly lightheaded and a funny character, he has an unstoppable sense of determination, optimism and commitment and will do anything to stand up for his friends and comrades. Along with that, he has great courage to back it up as well as unbelievable strength. Ever since consuming the devil fruit he was shown to be not worried about his inability to swim, much like his brother. Much of these traits are common among D's. His only display of true fear is towards his grandfather, to the point that he is intimidated at the mere mention of him.  Luffy never kills any of his enemies, no matter how cold-hearted they are; instead, he frequently sends the villain flying, knocking them out or beating them to a point that they are almost near death, which results in some of the villains searching for revenge, such as Buggy the Clown and Alvida. Oda explains that it's not a question of morality so much as a matter of punishing the villains for their crimes - he feels that killing the villains lets them off too lightly, whereas he considers letting them live to see their dreams be ruined a far more fitting punishment.  Luffy's dream is to find the One Piece and become Pirate King. He knows that to achieve his goal, he will have to defeat many strong opponents, including the World Government and his childhood hero Shanks.  Monkey D. Luffy is the son of Monkey D. Dragon, the leader of the Revolutionary Army and the world's most wanted criminal. His grandfather is "The Hero of The Marines", Vice Admiral Monkey D. Garp.   Before the start of the series, Dragon left Luffy in Garp's care. Dragon first appears after a lightning bolt suddenly destroys the gallows where Luffy was to be executed by Buggy the Clown and then saves Luffy from being captured by Captain Smoker. When he saved Luffy from Smoker, a mighty gust of eerie wind swept through Loguetown. It is undetermined whether or not he was the cause behind the gust of wind or the lightning; however, the story leads to believe there is more to him than it seems. Recently, he has taken over an island in the South Blue and is about to head to the North Blue when he commented, after noticing Luffy's newest bounty, given to him after invading Enies Lobby, that father and son will meet sometime soon. 

Luffy Monkey D.

Age: 18; 20 Birthdate: July 3, Cancer  Height: 169 cm (5' 6½”) Sizes: 95 - 55 - 85 Affiliation: Straw Hat Pirates (previously; Arlong Pirates) Position: Navigator Devil Fruit: none Bounty: 66,000,000 (previously: 16,000,000)   She is the first member of the Straw Hat Pirates to appear (in the anime), but the third to align herself with the crew, and the fifth to actually join. Possibly one of the best (or even the best) navigators currently sailing the Grand Line, she has the ability to recognize and analyze even the slightest changes in the weather through sheer intuition, thus saving the ship and the crew from the very unstable Grand Line weather on multiple occasions.  Nami has a tattoo on her left shoulder (a homage to her past), where she used to have a shark tattoo for being a member of Arlong's Crew. The new tattoo represents mikan (a fruit commonly know as tangerine) and pinwheels   She respects Luffy's qualities as a leader, but often gets angry of his irrational thinking and short attention span, even so she trusts him with her life. Despite the fact that Nami has deceived the crew, Luffy still trusts her enough to allow her to safe-keep his precious straw hat. She is almost always the one who gives orders on the ship (much to the Zoro's resentment) because of Luffy's usual lack of common sense. She often comically beats or hits her other crewmates for their nonsense, which occurs quite often. Robin is actually the only person Nami doesn't try to boss, and she refered to her as the only person who understands her, though in a comical fashion. She is very manipulative as well and can even turn an entire conversation in her favor when necessary, often putting on disguses and tricking the enemy. Acting as the "mother" of the crew, Nami doesn't understand or approve of the boys' often macho attitudes and principles. These are the only situations where Nami doesn't get the final word.   Nami's two favorite things are money and tangerines. She is greedy and will do anything, aside from abandoning or killing her friends, for money. Due to her past - After having gathered money for 8 years (and even before that often stole things), Nami is naturally accustomed to it, but thinks of her friends as more important. She is very manipulative, and often takes advantage of Sanji for his devotion to her and Usopp to maintain her weapons. Roronoa Zoro tries not to fall for her schemes, but ends up a victim like the rest, usually due to debt and blackmail. Nami also tries to avoid fights, and is one of the less adventurous and brave members of the crew. However, since the invention of her Clima Tact (A weapon that forms weather patterns), she is now seen fighting her own battles instead of becoming the 'easy target', as she doesn't want to be the one being saved anymore.

Nami

Name: Roronoa Zoro Age: 19; 21 Birthdate: November 11, Scorpio  Height: 178 cm (5'10") , 181 (5'11") (after timeskip) Affiliation: Straw Hat Pirates Position: Swordsman Devil Fruit: None Bounty: 320,000,000 (previously: 60,000,000 and 120,000,000)  Zoro was the first crew member to be recruited by Luffy. Zoro is a skilled swordsman who fights with his own unique sword style known as santoryu (three katana fighting style).This is achieved by using one katana in each hand and another in his mouth. He is also seen fighting with only one or two swords. When in a serious fight he ties his bandana, normally tied on the arm, on his head.   Though not a samurai, he appears to maintain a certain degree of bushido, and is frequently mistaken for one. Unlike Luffy and most of the other Straw Hat pirates, Zoro has been known to kill his opponents if he has to, though never in cold blood.  Zoro has a stern, serious and distanced personality, but, unlike Robin, he often reacts in a goofy and exaggerated comic style due to his gruff, impatient attitude. On the ship, he normally either trains with weights or sleeps. The only work he is seen doing regularly is hoisting the anchor using his great strength. He also likes sake, almost to the degree that Luffy likes meat, but like Nami, he never gets drunk due to his inhumanly-high endurance and tolerance for alcohol. Another notable trait is his lack of orientation, as Zoro often gets lost, even in small, familiar spaces or when being led by someone. Despite this, he is often the first to sense an enemy or danger, and the first to react. He is often displayed being well aware of dangerous situations and people around him.  Zoro often also reminds others of the harsh facts, which often shocks some of the other crew members, although they usually decide he is right. Zoro has also stated that he is an atheist, and has never believed in anything except himself. He often comes across as arrogant and overconfident, but only because he knows he's a strong man with great fighting ability. Even so, Zoro knows that he still has a lot of untapped potential, and is constantly seen training and trying to improve his fighting skills. He also adheres to a strict sword master's code of honor, and never falsely brags or lies about his abilities, sometimes outright admitting a weakness, even to an enemy. He also never tries to escape from a fight or use trickery to win, believing that doing so is cowardly and scorning anyone who uses such tactics. Zoro is very vigorous, strong-willed, and determined.

Zoro Roronoa

Name: Usopp Age: 17, 19 Birthdate: April 1, Aries  Height: 174 cm (5'8½") Affiliation: Straw Hat Pirates (previously; Usopp Pirates) Position: Sniper Devil Fruit: none Bounty: 200,000,000 (previously: 30,000,000) Likes: Being seen as a hero, the Going Merry, Adventure  Dislikes: Failure  Usopp is a liar and likes to play pranks on his crew members or just goof off with Luffy and Chopper. He loves to tell tall tales to Chopper (who believes him blindly) or anyone who's listening. The other aspect of Usopp besides his lying is his cowardice; he is a very timid person, or so he thinks. In extremely stressful situations, Usopp has proven to be far more courageous than he believes himself to be. He shows great resolve when his friends are threatened or mocked by outsiders. Even though he is a complete coward in battle (except as his alter ego, Sogeking), he is a useful part to the Straw Hat Pirates. He is extremely handy and can fix almost anything. He sometimes sees a role model in Zoro who never seems afraid but always proud. Usopp lacks a bit of self esteem and is often taken advantage of by Nami to make her weapons or repair and improve them - something he is very adept at, having constructed the ingenious weapon "Clima Tact."  Usopp will also stand up and fight for not only the well-being of people, but also for their ideals - and the ideals of a pirate, which he holds very high. In battle he normally tries to trick his enemy by telling tales or mischievous lies to deceive them. Despite his lack of physical strength compared to other members of the crew, Usopp seems to be just as resilient as his comrades and this ability to bear loads and loads of damage, is one of his best traits, in addition to his cunning and intelligence, which has saved the Straw Hats on many occasions. Also, Usopp has outstanding marksmanship abilities with his slingshot and is on his way to becoming one of the best snipers in the One Piece world, although his goal in life is to become a proud and strong pirate like his father Yasopp of the Red Haired Pirate Crew.

Usopp

Name: Sanji Age: 19; 21 Birthdate: March 2 ; Pisces Height: 177 cm (5' 9") Blood Type: RH- Affiliation: Straw Hat Pirates (previously; Baratie) Position: Cook Devil Fruit: none Bounty:177,000,000 (previously: 77,000,000)   Sanji is the chain-smoking chef of the Straw Hat Pirate Crew. He has superb fighting skills that only make use of his legs, in an effort to minimize damage to his hands which would impair his cooking skills.Except a single fight where he uses knives against a fellow chef. Sanji uses an array of powerful and varied kicking moves when he fights. His cooking skills are world class, and he was mentored in both cooking and fighting by Chef "Red Leg" Zeff of the Baratie. He was born in the North Blue, but grew up in the East Blue.  Sanji is trash-talking and serious, and usually gruff and impatient, especially around men. This is contrasted by his "love-cook" side, as he is very amorous around women. Sanji is completely devoted to any beautiful woman, usually losing all common sense and composure in front of them, then attempting to comically swoon them. This behavior has earned him the nickname "ero-cook", or perverted cook. He can also be very chivalrous and gentlemanly around woman, volunteering to help them in various tasks and situations, whether they need help or not. He has sworn to never let insult or injury happen to any woman while he can still stand, even if that woman is trying to kill him. This is often problematic in his fighting as he can't attack female opponents, and would rather die than hurt them. All this is apparently the result of a "strict upbringing". To contradict his gentlemanly behavior, Sanji also enjoys seeing women wear skimpy clothing, and can be a voyeur.  His goal in life is to find the All Blue, a legendary ocean, which contains all the fish in the world. As such, it would be paradise for any cook with as much love for his work as Sanji, who holds great respect for the tools, ingredients, and art of cooking. So great is his devotion to his calling, that Sanji will not let any person or creature starve, regardless of them being friend or foe.  Being the crew's chef, he looks out for the health of his crew mates. Sanji respects Luffy as a captain, but often gets angry at him for eating too much, showing disrespect for the aesthetics of cooking, and generally being daft and irresponsible. He is constantly in petty fights with Zoro (sometimes calling him Marimo) over each others' traits and they have developed a rivalry, but have managed to make a devastating team together. He is very protective of the female crew members and Nami likes to take advantage of him, exploiting his extreme servility. Sanji originally wanted to cook Chopper, but has come to respect him as a crew member and friend. He's also good friends with Usopp; they team up and interact often, and Sanji understands him quite well. In short, he cares as much for the crew as any Straw Hat should, but unlike Zoro, Sanji shows these feelings more.  It is revealed that Sanji is the third son of the Vinsmokes, a family of killers. His father and one of the Yonkou, Big Mom, has arranged a marriage between him and the 35th daughter of the Charlotte family, Pudding.

One Piece: Umi no Heso no Daibouken-hen Characters