Robin

Out of all the members of the Straw Hat Pirates, Robin is the most serene and has rarely been seen to act comically. She approaches life and the world at large in a calm and collected manner and is overall one of the least emotional members of the crew. She treats Luffy with more respect than the most of the crew, even when he acts impulsively, to the point where she will smile and laugh at his antics rather than berate him. Together with Zoro, she is one of the members that support Luffy's decisions unconditionally.

When the crew is sailing, Robin is usually reading and investigating data from the places they visit. She is very wise and very patient in everything. Robin does not play a specific role in the ship, but she can foresee what can be found somewhere and that (in her own words), is of advantage to others. Luffy considers her a very intelligent member.

Through her heritage on the island of scholars, Robin is an archaeologist and historian who seeks the comfort and freedom to study the mysteries of the world. She is the quieter, more reserved crew member, rarely having outbursts of emotions (occasional exceptions being sweat drops, and when she cried out to Luffy and the Straw Hats from the Tower of Justice during the Enies Lobby Arc). She even appears calm while speaking ominously around her crewmates. She has an "adult charm" about her, as stated by Sanji. Being described as the "mother" by Oda, she in kind has shown maternal care for younger characters like Chopper, Momonosuke, and Toko.

“ Robin: The things you have destroyed back there were priceless artifacts. Precious treasure whose importance cannot be measured... History may always be repeating itself, but humans cannot go back into the past... you wouldn't understand that, would you? Yama: I... I understand... I won't... do it again... Forgive...

Robin: No. ” — Robin punishes Yama for destroying Skypiea's ruins.

Being an archeologist, Robin is highly passionate about the world's history and uncovering the mysteries of its past. As such, she does not tolerate people who regard history as meaningless or destroy objects of historical significance. She became furious at Yama because he destroyed valuable artifacts from Shandora, and swiftly defeated him after. She shows little interest in the Ancient Weapons that individuals such as Crocodile and Spandam seek. However, she might be the only one who is able to awaken them.

Calm Demeanor Both in and out of battle, Robin tends to maintain a relaxed demeanor that only seems to change whenever circumstances prove to be far beyond what she can handle (i.e., a hopeless situation). More often than not, however, she exhibits nigh-unshakable calmness and reserved behavior against inferior adversaries, to the point where she typically displays by using her powers to satisfy minor necessities (i.e., using a pair of arms sprouting from the ground to form a make-shift seat).

As a result of her violent past, she is very merciless in combat and does not shy away from using lethal force. She will break the necks or spines of her enemies without hesitation, even when they cry for forgiveness, as demonstrated when she in her fight against Yama. Despite her tendency to remain calm and collected, she can be quite intimidating and forceful when she wishes, as demonstrated when she essentially forces Brook to stop fooling around and continue his explanation. She even states her willingness to be a demon if she has to be, especially for the people counting on her.

Robin's Face Fault Robin making a comically shocked face for the first time.

Despite Robin's ability to cope with the bizarre, she was unable to take in the idea of Dwarves and was even shocked by their nature of easily trusting people, something she usually laughs off whenever Luffy does it. Robin was originally the only member of the crew to possess no face-faults. However, after arriving at Dressrosa, her significant change in personality begins to present itself. Robin has since expressed multiple face-faults, demonstrating that she is no longer the stoic, uncompromising individual she used to be. Robin was also overcome with emotion at the sight of Kanjuro's Nobori Ryu technique, which produced a pitiful-looking dragon that she found to be overwhelmingly cute to the point of blushing, whom the crew soon dubbed "Ryunosuke". She was moved to tears at its noble effort to climb Zou's hind leg to the top, struggling because of its feeble features, and then honored its memory when it turned back into a drawing and ceased to be "alive" by placing flowers on its "grave" where it had reverted to drawing form.

Morbid Behavior Robin has a somewhat macabre side to her, and often points out gross or morbid facts, usually to the disgust of Nami or Usopp. Robin will usually be the first to speculate that a crewmate has met or will meet with a horrible fate, often going into grisly detail. In other instances, she will express enthusiasm for anything with a horror theme.