Acacia was born in Slateport City to two successful engineers. He and his two older siblings all shared a passion for Pokémon training and were competitive with each other from a young age. His sister Willow and brother Cypress easily befriended Pokémon when they were little, but Acacia was young and experienced a lot of difficulty trying to catch one. He feel behind Willow with her Eevee and Cypress with his Cubone in terms of Pokémon training.
Years later, after both older siblings had begun their journeys, a ship docked in Slateport, containing the renowned scientist Blaine from Kanto who had come to Hoenn in order to study volcanic patterns. Acacia’s parents were friends with the man, knowing each other through work and had him over for dinner. Acacia quickly became infatuated with the man, especially his Arcanine, and followed Blaine closely for the entire duration of his trip.
When it was time for Blaine to leave Acacia became extremely saddened and begged him not to go. Blaine suggested the young boy simply come with him and study as an apprentice. After hours of pleading combined with some convincing from Blaine, his parents reluctantly agreed. Acacia was only 8 when he left to go live with Blaine.
After two years of living on Cinnabar Island, Acacia had learned a lot from Blaine, and had established a good relationship with a Growlithe Blaine had specially bred and trained with the Growlithe to practice his battling abilities. For his tenth birthday Blaine provided Acacia with a boat ticket to Pallet Town, telling him it was the best place to start his journey, along with his own PokéNav Plus so he could keep in touch.
Acacia arrived in Pallet and instantly bonded with the Squirtle in the Professor’s lab, much to Blaine’s dismay that he opted not to take the fire type. Together they traveled, not facing too much difficulty in their gym challenges. Surge was the first real adversity the duo faced, but luckily they prevailed when Squirtle evolved and was able to barley defeat Raichu.
Acacia had his first gym battle loss in Celadon and was very upset about it, calling Blaine to tell him about it. After giving the young trainer some motivational advice he sent Acacia the growlithe he had bonded with, providing him with a favorable matchup against the grass type gym that allowed him to emerge victorious. After that he continued to build up a Pokémon team, including a lonely ghastly from lavender town and a dratini he won from the game corner, and battled his way through the kanto gyms, qualifying for the Indigo Plateau Conference. Acacia battled well in the tournament but lost to his older brother, Cypress, finishing in the top 8, when his Dragonair was defeated by Cypress’s Flygon.
After suffering a crushing defeat at the hands of his older brother, Acacia vowed to become stronger and set out to the Kalos region to train. He had completed the gym challenge and placed in the top 4 in the Lumiouse Conference, losing to a trainer with a mega Ampharos. Acacia then continued to train and had grown fond of the battle chateau and spent much of his time there training, eventually earning the prestigious rank of duke. One day another duke came in who claimed to be a water type master. It was Siebold, the Kalos elite four member and water type master. He had heard stories of the power of mega evolution, but was only now witnessing it to its power first hand. Acacia watched in awe as Siebold and his mega blastoise defeated challengers in an almost effortless fashion.
After Siebold was finished battling, Acacia ran up to him and begged Siebold to teach him the secrets of mega evolution. Siebold agreed, but said Acacia would only be worthy of mega evolution if he and his blastoise could defeat him without the aid of mega evolution. Acacia accepted the terms and the two sent out their blastoises to engage in battle. It was a long and hard fought battle, but it primarily consisted of Acacia defending Siebold’s attacks, never taking the opportunity to gain the offensive. Eventually Acacia’s blastoise fell and he was greatly saddened. Siebold confronted the young trainer and explained that Blastoise was an extremely well trained Pokémon and the loss was Acacia’s fault rather than a difference in Pokémon strength. The water type master instructed Acacia to strengthen himself as a trainer and return in a year for a rematch.
Motivated to become stronger, Acacia sought out traveled to the Hoenn region where he completed the gym challenge and rounded out his Pokémon team. He then entered in the Ever Grande conference, this time losing to his sister in the semi finals. After their battle, Willow congratulated her brother on a well fought battle and offered him a Sneasel egg as well as an invitation to the battle resort. Acacia gratefully accepted both proceeded to train at the battle resort for the remainder of the year. Upon returning to Kalos to battle Siebold, he lost again but this time in closer, but still one-sided battle. Siebold again told him that he must become a stronger trainer and told him to return in another year.
Acacia traveled to Unova but did not participate in the Unova league. Instead, he opted to compete frequently in the Pokémon World Tournaments held in Driftveil City. Acacia did well in those tournaments, winning a large amount of them and earned the nickname “The Innovator” for his ability to constantly improve on his own strategies to adapt in battle. His accomplishments at such a young age gained the attention of many, including the former champion Alder. Alder sent Acacia a letter, telling him to meet him at Pledge Grove where they would battle. Acacia accepted and battled the trainer but was swiftly defeated. Alder liked the trainers persistent spirit and offered that he stay with him a year and train. Acacia quickly accepted and informed Siebold that he would need to wait another year for a rematch. Alder brought Acacia to the wild area in galar and put him and his Pokémon through grueling training everyday in raid battles and other feats of strength, including taking on the Galar gym challenge, and at the end of each week they would have a battle. Progress was difficult but by the end of the year the battles were evenly matched, with it not being a surprise for Acacia to win.
After thanking Alder for all he had done, Acacia returned to Kalos for his rematch against Siebold. It was an intense battle between the two blastoises that lasted 5 hours, with neither willing to give an inch. Both Pokémon were extremely exhausted and about to pass out when Acacia suddenly returned his blastoise to his pokeball, claiming it had already been through enough and mega evolution was not worth severely damaging his friend. Siebold was impressed that the young trained would forfeit the match and such power out of love for his Pokémon and deemed Acacia worthy of the power of mega evolution, handing him a key stone bracelet and giving blastoise a metal bracelet containing a blastoisite. Acacia gratefully accepted and went on his way.
Acacia competed in the Indigo Plateau Conference once more, defeating both of his siblings on the way, and narrowly winning the finals with the power of mega evolution on his side.
With the money he won Acacia bought an apartment in Circhester and enjoyed his time their while frequently competing in top level tournaments in Wyndon. One day while fishing in Hulbury, Acacia encountered a Pichu that had washed up on shore that looked rather exhausted. In its hand it tightly clutched a strange crystal that Acacia did not recognize. Upon asking a friend, Acacia was told that it was called a Z-Crystal that was said to unlock amazing power from Pokémon in Alola.
Intrigued and excited by the prospect of more adventures, Acacia instantly flew to the Alola region with the Pichu, hoping to find Pichu’s home and grow stronger along the way. It was once he landed in Alola that Acacia learned the typical journey trainers took through the region was called the trial challenge. He thoroughly enjoyed the fun alternative to the traditional gym challenge and collected many crystals similar to the one Pichu held. His friendship with his new travel partner blossomed throughout their journey and the Pichu evolved into a Pikachu. Once he reached Poni Island, Acacia encountered a veteran trainer who recognized the Pikachu in an instant. He was impressed by Acacia’s ability to pass the trials without the help of Z-moves and recognized that a strong bond must have been formed in order to have Pichu evolve. To show his gratitude for making sure the Pikachu was safe and happy, the veteran gifted the Pokémon to Acacia so it could continue having fun adventures. He also gave Acacia a thunder stone and his old Z-ring equipped with an Aloraichium-Z, which he taught Acacia how to use after evolving the Pikachu.
Now armed with the ability to use Z-moves and the final member of his team, Acacia was advised to take on the Battle Tree. Though the fights against the legendary trainers that often visited were brutal, Acacia fell in love with the island life and built a small cabin in the Poni Meadows that he frequently vacations at to participate in the Battle Tree in order to hone his skills.