Roxanne is in charge of the Stone Badge, and resides in Rustboro City. She is an expert on Rock-type Pokémon, as shown from her name, which may be derived from the word rocks. Her name in Japanese language versions means azalea, but is also an allusion to the Japanese word meaning "throwing stone" (礫, tsubute?). In the Pokémon Adventures manga, Roxanne is both the Rustboro City Gym Leader and an instructor at the Rustboro Trainer's School. She has appeared in "VS. Nosepass" Parts 1 & 2 (Ch.190 & Ch.191), "VS. Shiftry" (Ch.222) and "VS. Kyogre & Groudon X" (Ch.248), appearing as either the Gym Leader of Rustboro (where she supplements the traditional head-to-head challenge with written tests), or fighting against Team Aqua and Team Magma with the other Gym Leaders from Hoenn. In the Pokémon anime, Roxanne is not only a Gym Leader, but also a teacher at the Pokémon Trainer's School in Rustboro City, teaching skills she learned as Professor Oak's star pupil. She teaches an introductory course on Pokémon to young children not old enough to be trainers. She appears in episodes 291 and 292, "Gonna Rule The School!" and "Winner By A Nosepass". While "Gonna Rule The School!" introduces Roxanne in passing, it instead focuses on members of her class; in "Winner By A Nosepass", Pikachu and Ash use a previously learned (and unreliable in the early anime) attack, "Iron Tail", which Pikachu later uses to defeat Roxanne's Nosepass in a battle for the Stone Badge.She also looks up to Brock as the most powerful rock gym leader.
Maylene (Sumomo in original Japanese language versions) is the young Gym Leader of Veilstone City and specializes in Fighting-types. Her name refers to the word "melee" which relates to her fighting styles. In the game the player is required to solve a puzzle to clear the path to her, battling gym trainers, which focus on Fighting-type Pokémon along the way. Maylene's Pokémon are Meditite (Lv. 27), Machoke (Lv. 27) and Lucario (Lv. 30). She awards the Cobble Badge to trainers who defeat her. In the game, her father is seen playing at the Casino in Veilstone City. When the player talks to him he will tell him or her about his daughter who he describes as a tough one. Maylene's first appearance is on DP66, "Lost Leader Strategy". When Ash and friends reached Veilstone City, they saw a girl there, training with a Lucario. Later, it was introduced that she was Maylene, the Veistone City Gymleader. Ash asked immediately for a battle, but Maylene refused the request because of Paul. She also appeared in DP67, "Crossing the Battle Line!", where Maylene battled Dawn using her Lucario, Meditite and Machoke. She later appeared in DP68,"A Triple Fighting Chance!", where Ash battled Maylene and won the Cobble Badge. from wikipedia
Francesca performs with three Chingling. One of them, wearing a green ribbon, seems to have a little more personality than the other two, being very energetic. It loves to meet new people and will hug them. Francesca tries to use it in battle but it's a little weak. Her training exercises are very difficult even though she is dealing with small Pokémon. Team Rocket kidnap her three Chingling. James grows fond of the Chingling wearing the green ribbon as it reminds him of his own Chimecho. Later on, Francesca gains more confidence in Chingling and is able to battle against James and Mime Jr. with it and win.
She takes care of a Bibarel for the Expert. She's been friends with it since she was a girl. The Expert is responsible for building the new bridge. She was appointed to look after Bibarel and organize the workers temporarily when the Expert is out. Bibarel stopped working immediately after the departure of the Expert. She was extremely depressed and blamed herself for not being able to gain the trust from a childhood friend. Brock tried to solve the situation by giving his specially designed Pokémon food, which will make Pokémon become energetic, to Bibarel but it went back to sleep at once after taking the food. This depressed Brock as well. Later, the boss constructor came with a building machine and requested to take the job. Bibarel became furious and tried his best to stop the constructor from building the bridge. The Expert came back and told the group that the bridge isn't planned well and will fell down easily. He brought the group with a new blueprint and explained that he was old to investigate about this. Isis realized that Bibarel is actually trying to protect the lives of people and became friends with Bibarel again.
She appears in "Some Enchanted Sweetening", "The Grass-Type is Always Greener!", and "An Angry Combeenation". She is a descendant of a family of treasure hunters and is looking for Honey in the Eterna Forest by using a Mothim. (Bulbapedia)
Khoury (Japanese: カズナリ Kazunari) is a Trainer from Johto as well as a friend of Lyra's. They both debuted in An Egg Scramble!. Khoury traveled to Sinnoh with Lyra and his father where they all took part in the Johto Festival. He wanted to visit Sinnoh so that he could observe and hopefully catch the native Pokémon. He was also interested in learning about Pokémon breeding and asked if Brock would mentor him. Khoury tends to panic very easily but is always very excited to meet a new Pokémon. In A Rivalry to Gible On!, after encountering a wild Gible, Khoury became determined to capture it to raise it into "an awesome Gabite," which he eventually did after a closely-fought competition with Ash who had the same goal. In Bagged Then Tagged!, he had a tag battle with Lyra against Ash and Dawn. Despite his Totodile evolving into Croconaw during the match, he and Lyra eventually lost. At the end, Khoury, his father, and Lyra left on a blimp headed to Johto and said their good-byes. Khoury had also agreed to become Lyra's traveling buddy, upon her request. Source: http://bulbapedia.bulbagarden.net/wiki/Khoury
He is a wandering minstrel who enjoys music and as such carries his golden harp with him always, which is shaped like a Mew. During battles, he is calm, and prefers to give commands without shouting, although his commands are more like asking politely. He made his debut appearance in Dawn of a New Era!. At the time, he was confused as to whether he should challenge gyms or become a Pokémon Coordinator and didn't know what path to take. He battled both Ash and Dawn with his Budew, which evolved into Roselia during his battle with Ash. After the battle, Nando decided to become a Pokémon Trainer as well as a Coordinator. He later appears again in A Secret Sphere of Influence!, where he is falsely accused and arrested due to Jessie, James, and Meowth's stealing of the Adamant Orb. Nando also appeared in Dawn's Early Night where he entered the Hearthome Contest, which he won by defeating Zoey. Nando made a cameo in A Breed Stampede! alongside with Kenny in Marian's news report about coordinators. According to The Greatest - Everyday!, Nando will compete in both the Sinnoh Grand Festival and the Sinnoh League Conference.