Just so I'm fair to both sexes, I'll talk about a male character now. Don't worry, I do plan to talk about more girls later, but this guy kinda stands out. Who? Satoru Akashi the Fiery Adventurer, AKA Bouken Red
This is the lead character of Boukenger, obviously the leader. He's a renowned adventurer known as 'Immortal Fang'. While he acts cool, when situation calls in, he's just as hot blooded as you can expect from the one calling himself 'Fiery Adventurer'. His favorite saying is 'Attack!', which is used to rile the Boukengers up to take action. He gets along well with his teammates, although he wasn't above tricking them if it was for the greater good. So let's dig in to this guy...
Satoru did have to claw his way out to become the 'Immortal Fang'. He was once a trio of adventurers with his friends to search for Precious. However, during one trip, there was a disaster and when he tried calling for help, the site where he ventured to caved in, killing his friends. Thus, Satoru has carried some sort of guilt complex by being the lone survivor from the event. However, he promised that he'd keep his adventure spirit intact to honor them.
Satoru is later recruited by SGS and becomes the first Boukenger. He went ahead and eventually recruited Sakura Nishihori and Souta Mogami, before eventually recruiting Masumi Inou and Natsuki Mamiya. He was very invested in his job and takes it well.
Unlike Sakura, Satoru doesn't develop from his 'by the book' attitude. In fact, he's pretty open to breaking the rules sometimes. He remains the same throughout Boukenger, except maybe that time when the Questers had him hallucinate about his dead friend, causing him to doubt his worth as an adventurer. However, he eventually came to the conclusion that he ventures because he likes it rather than continuing his friends' legacy.
Satoru often gets into fight with Ryuuon. This is most likely intentional, in a way that Ryuuon was also an adventurer, but a darker take of Satoru. Ryuuon is what happened if Satoru wasn't surrounded with good friends and instead got bad friends who constantly humiliate him and eventually lost what's fun about adventuring and got a twisted take on it. You may say Ryuuon is Satoru's shadow that he managed to conquer, but as another man rather than something born of Satoru. And however a bastard Ryuuon was, Satoru still believed he could still see the light and offer him a chance of redemption... which was promptly shot down to hell by Ryuuon himself.
Satoru is a calm, cool leader, but as said above, he's hotblooded on the inside. His tendency to say 'Attack!' is also distinctive that his teammates teased about it or mimic it. He's also hellishly competitive, offering Masumi a lot of challenges, but mostly to teach him some good lessons.
However, one thing that makes Satoru stand out amongst Red Rangers is that he's got a big ego and was rather obsessive about it. He can't stand it if people laugh at him at his expense, and it's not like he never made any mistakes or embarrassment worth laughing at. How many times has it been that Satoru did something silly, his friends laugh at him and he yells "NO LAUGHIIINGG!!" to stop them for no avail? This is why Satoru is usually considered an example that "Just because you're the Red, doesn't mean you can't escape being treated like a joke for amusement."
About his ego further, there's also that incident when he tried enrolling to an Adventure school, but thought he failed, crushing him thoroughly and spent half the episode in a slight catatonic state (or in the terms of TV Tropes: Heroic BSOD), thinking that if you take adventure out of him, what will become of Akashi? Of course this was fixed soon and he's back on spirits.
He's also anti-superstition, which got him on a predicament when he's hit with extreme bad luck. Always thinking that it was only chance, the constant bad luck crushed his ego. With the support of his friends, he was able to reshape that ego, and STILL act like he's anti-superstition, only to be proved otherwise... for laughs.
And as much as hotblooded or calm he is, he's got a sensitive side. He was filling in the role of the 'grandma' for the Momotaro stand in, and he starts acting like it, giving soft treatments instead of Eiji's harsher treatment as the 'grandpa'. And when Momotaro left, Satoru was left bawling uncontrollably, like a mother who just saw her child off.
It should be of no surprise here. While he treats Natsuki well, she's more involved with Masumi so Satoru is probably just another big brother figure for her. However, when it comes to Sakura, it is no doubt that they are the intended couple. Satoru wasn't really interested in love, but he appreciates Sakura very much, who held a crush on him. He was really concerned at her during Gekiranger vs Boukenger arc when Pachacamac XII possessed Sakura and forced him to do many atrocities. Satoru was really against it, but he had to do the dirty job to protect Sakura. Guess it shows that he cared... although he probably would do the same if it wasn't Sakura as well.
In conclusion, there we go about Satoru. Hot blooded, Calm, Sensitive, and again with the TV Tropes term, a Butt Monkey even if he's the leader. He's far from being a favorite of mine, but he's quirky enough to warrant being talked about here. I'll be seeing you soon for another talk!