queen otohime and fisher tiger are two sides of the same tragic coin.
within this volume, we get to see the two heroes of fish-men island, however they represent two sides to the human and fish-men conflict.
fisher tiger, the adventurer, was most famed for freeing the slaves of marijoa, no matter their race. of course this is an excellent deed, and the whole of fish-men island revered him for his almost impossible task, it however drove a wider gap between the fish-men and humans. the celestial dragons, who enslaved the fish-men (and humans) are the world nobles, and anyone who came up against them will be duly sorry. by freeing the slaves, as a fish-man, fisher tiger defies the celestial dragons, further proving to them that fish-men are monstrous, untameable beasts. queen otohime recognises this, that if fisher tiger frees the slaves - which is considerably a good thing - he will turn the celestial dragons against the fish-men, even more than they already are, but she could not deny that she heard the pain in his heart, so she did not intervene. because of the nature of the slaves, being property of the world nobles, they could not return to normal living, and world instead have to be outcasts, so fisher tiger started the pirate group, the sun pirates, as a way for the slaves to go on living securely, within a group of outlaws. although some of the sun pirates did not want to be criminals, they had to because it was that or enslavement. fisher tiger becoming the captain of the sun pirates and causing mayhem on the oceans were the humans also dwelled infused the notion that fish-men are dangerous and a threat to human existence. this negatively impacted queen otohime's chances of trying to get the residents of fish-men island to sign the petition to emigrate and live among the humans, because of the reputation fisher tiger had gained as a pirate and fish-man, and because of the stories of enslavement and prejudice that they had heard from him, the fish-men did not warm to otohime's idea of peace with the humans, because they had treated them badly.
however, despite this, otohime and tiger both wanted the same things, although their experiences hindered their values. tiger, although fighting against the humans and the navy as a pirate, always refused his crewmembers to kill. he believed that if they killed them for the simple crime of being human, aside from anything else, then they were no better than them. if they kill, they lose, because they are kneeling to their hatred, which would be too close to the human nature he had witnessed. otohime had similar values, she always helped the shipwrecked humans on fish-men island, and went as far to protect a celestial dragon that threatened her citizens and even her. she told the fish-men who tried to kill the world noble to drop their guns, because there are children watching, the children who do not know of the history before hand, of the prejudice and hate between the humans and fish-men, and therefore these children were the hopes of the future of peace among the two groups. if they were shown violence and hate against the humans, then they too will react in similar ways.
otohime's values were less complicated compared to tiger's. otohime campaigned for peace among the two species and believed that if they the first to forgive, they will get closer to the humans. that they fear what they do not know, and they only know a small sample of humans. tiger's feelings were a little more complicated. as a former slave, he could never feel it in himself to forgive humans and what they did to him, but if he let his hatred and revenge control him, he is no better than the humans, so he urged his crew to look past the history and not persecute humans for being humans.
jinbe and arlong of tiger's crew inherited tiger's will, however differently. jinbe understood tiger's wish to want to get along with the humans, but that he physically couldn't because of what they did to him. jinbe inherited tiger's hope for a peaceful future, and changed his ways to allow himself to be driven by it, to befriend humans, such as koala, luffy and ace. arlong, however, inherited tiger's hate, he saw how tiger refused the blood transfusion from the humans because he could not stand to have his persecutor's blood run through his veins, and for that reason tiger died. although tiger's last words encouraged his crew to not hold human's at fault for his death and to not be led by revenge and hatred (which jinbe and many others understood), arlong could not look past that because of tiger's hate for humans, he died, and instead took it to heart, hence why we see arlong's actions in coco village at the beginning of the series.
so, although they wanted the same things, circumstances led them to have different final outcomes. and the fact that both otohime and tiger died at the hands of humans (allegedly), set back the progression for fish-men and human friendship massively.
i also find it interesting how the sun is the symbol of hope and freedom. tiger branding his crew as the 'sun pirates' and marking over the former slave symbol burned on them with a sun. otohime's speech about how the fish-men could live anywhere on the vast, vast sea floor, and yet they choose to live in the one spot where the sun reached 33,000 feet below. also (with the gift of hindsight) we know about the sun god nika, the warrior of liberation and freedom, or known as joyboy. the sun representing freedom, and the fact that the main force for the fish-men to emigrate is so that they could feel the sun themselves, without the water between them, is a very touching notion. it's to say that the sun ends up shining on everyone, no matter where they are, it does not discriminate, the son is freedom.