After many requests, I decided to do this. It makes more sense to compare Rocky, Adam and Aisha with the Japanese counterparts because I didn't do it the first time. I didn't do this at first because season 2 was not at all directly adapted or related to Dairanger. But I guess it would be interesting to see if by any coincidence if they were similar.
Jason / Rocky / RyouRyou was a stalwart leader but also knew how to have fun. At first, he was like a fish out of water, new to the whole chi-thing and the Gorma/Dai war. Ryou had a big heart and had a soft spot for Jin, who he ultimately fought and then forgave and kept helping. Jason was a stalwart leader as well, they were both great fighters but Ryou went through more drama---his father betrayed his teammates to go with evil, and that whole Jin drama. Rocky didn't get much characterization when he was first introduced until Zeo, where he became the joker, except for that one episode where all he wanted to do was play. I love Rocky but he was bit bland and not leader-like in season two.
Zack / Adam / DaigoDaigo was the green one, Shishiranger, and Adam was the Black Ranger. The green lion became the black Lion zord, but he was green on the show and the toy was black. I personally believe Adam and Daigo were similar, in that they were both sensitive. Daigo fell for Kujaku, an immortal with Peacock powers out for revenge on Gorma villainess Gara and was distracted by it and would do anything for her. Adam was shy, Daigo was kind of shy, he mediated and was a strong fighter. Zack was more playful and outgoing. But Zack was a sucker for girls too.
Trini / Aisha / KazuWhile Kazu was male, because he was a hairdresser, he was believed to be gay, but there wasn't any real evidence for that and I've mentioned this before on my post about homoerotism in Sentai. Anyhoo, Aisha was bubbly and infectious and sometimes got carried away with things. Because she was African-American, she had to have 'attitude' and say stuff like "I heard that." She was the most talkative of the new trio. Trini was a woman sure of herself and knew who she was. Kazu was the same way, he was confidant and tried being optimistic. He was a poor farm boy who came to the city to survive on his own and became a posh rich-looking man.
Billy / ShoujiShouji was a cocky everyman, a man's man, he enjoyed many sports and was a skirt chaser. Billy was incredibly intelligent and by season two, he started loosing the glasses and looking more pumped up and handsome, wearing more tanktops. Shouji wasn't so book-smart, but he was a bit street-smart when it came to last minute strategies. Billy always thought things out.
Kimberly / LinLin was half Chinese and Japanese and came to Japan from China to join the Dairanger. She was the one to discover the Chi Beasts (Thunderzords) and was the heart of the team. She was forced to take in Kou into her apartment when she didn't want to. She eventually warmed up to him. Lin was like a surrogate mother to him at times and protected him. She had an eccentric uncle who married a younger woman, which she did not like at first and her uncle even seemingly killed a man--which was later proved wrong. In season two, bubbly Kimberly had to deal with the loss of her boyfriend (when he lost his powers and moved away) and then to the shock that he was the new White Ranger and then the loss of three of her old friends. Kimberly then traveled to the past and had to play the leader to four ancestors of her teammates. They were slightly different in personality.
Tommy / KouOkay, this is the one everyone wants to see. Everyone likes to point out that Kou was a kid, but he had to put up with a lot of drama, even tough for an adult. Kou was orphaned and lived with foster parents and then had to live with an older hot stranger for a woman. He falls for a girl that turns out to be a villain child, who then turns out to be his twin brother. He was haunted by the memory of his mother burning a tiger symbol on his arm and shocked to find out he was a twin. Tommy, was traumatized by the fact of loosing his powers and then gets the honor of being the White Ranger and the leader of his friends. While Saba didn't talk much, he had a funny accent, Byakkoshinken spoke for Kibaranger to mask his child voice from the Dairanger and his villains and gave advice to Kou--which he would sometimes ignore. They were very different, in not only in ages but in what they had to deal with. Kou had to deal with fighting his twin brother, while Tommy had to deal with being stuck in a storybook.
UPDATED 11/22/09Kameo/Daimugen / Tor the Shuttle ZordTor was just a zord like Titanus introduced in season 2 and never seen again after that. We saw some footage of a tortoise touching a crystal in the viewing globe. That was actually Kameo, an ordinary man who became a real tortoise by the large gem and then into Daimugen. In actuallity, Kameo was Daimugen to begin with, but because he was immortal, and after the first Dai/Gorma war, he forgot who he was and lived as an ordinary man. He was bewildered and shocked by what was going on. There was two actors that played him, one of them being Yellow Owl in Jetman. Kameo was friends with Kazu.
UPDATED 11/12/09Thanks to Sean Akizuki, I remember a couple other comparisons:
Serpentra / DaijinryuuDaijinryuu was a god from space that felt disturbed by the noise made by the dairanger and Gorma [evil] and tried to make them shut up... by destroying the city. Daijinryuu is neither good nor evil, but it did hypnotize citizens and tried to make them commit suicide, luckily they were saved. Serpentra was Lord Zedd's war zord that eventually became a wedding carriage for him and Rita. It later was dug up in "Forever Red" and destroyed by a flying bike.
Mondo the Magician / ShaadamShaadam was the main villain in dairanger, the footage of him fighting the dairenoh in his silver face was changed into Mondo the Magician fighting the Thunder Megazord. Mondo was said to be an old friend of Rita's but he lived in a storybook. Shaadam was a clay clone of a real Gorma general that had fathered twins... one that went to work for the Gorma [Akomaru] and Kou, Kibaranger. He ended up becoming a Emperor and abusing the power of a crystal and dying.
Needlenose / General CactusI decided to also show the differences between some other monsters. Just some. Needlenose was created from a cactus Tommy gave Kimberly by Zedd and went with Goldar to the old west to disturb the ancestors of the Rangers. He spoke with a Mexican accent and destroyed, like every other monster. General Cactus was very different, he was a pedophile, he loved little girls and kidnapped them, paralyzed them and used them as dolls. He also acted a bit feminine, I don't know if it was old Japanese thinking [back in the 90's] that if you act feminine, you are gay. But I don't dwell too much on that, since he targeted little girls. He thankfully was destroyed.
Silver Horns / Repellator / ThunderThunder was the personal carriage for Akomaru, an evil little kid that later turned out to be Kibaranger's twin brother. He would ride on his back. Silver Horns was just a monster that Lord Zedd sent when Aisha, Rocky, and Adam joined the team. The suit was used again and repainted and a tongue was added for Repellator. He fought a sick Kimberly during the Masked Rider 3-parter in Season 3.
Skelerna / JinSkelerna was just a random monster that the Rangers fought and since the footage was limited, he didn't really touch them physically [Like many of the latter season 2 monsters]. He didn't have a Megazord battle [He was destroyed by the newly revealed Power Cannon]. Jin was an assassin that Ryou had a rivalry with. Jin made a deal with the evil--Gorma, and was later turned into a vampiric monster that attacked people at night. It truly was a dark portrayal. The two were drastically different. Jin only cared for himself, he even killed his only love in the name of evil. Jin eventually died.
Click here to see all the other comparisons I made