

Greninja became a unique Pokémon of Ash after its hidden potential was unleashed in its Ash-Greninja form, he gained considerably more power, endurance and speed. After that, Greninja and Ash fully came to understand each other. However, after fully synchronizing their feelings to save a Spewpa from falling, Ash explained to Greninja why he chose to be a Pokémon master and he views Pokémon as friends. While Greninja was recovering from the battle, he also felt responsible for making Ash lose the battle. When Ash left Greninja in the Pokémon Center out of guilt for losing against Wulfric, Greninja gave chase to look for his trainer. One of Greninja's greatest insecurities was his close bond with Ash, as failing to perfect the Ash-Greninja form took a toll on both Ash and Greninja alike. For example, when everyone got separated after an attack from angry Pangoro, Frogadier stepped forth and protected Serena and Chespin.


Greninja is also very protective towards others and is willing to keep them protected from harm. For example, when he used its Frubbles to tidy up Fennekin's tail, she thanked Froakie for his thoughtfulness. Greninja even has the tendency to blush when he is thanked and praised by other Pokémon and people. He finally chose Ash after seeing his bravery and being shown love. He ended up going through several trainers, but they all failed to live up to his standards. After he was healed by Nurse Joy, he realized that in order to become strong, he need a trainer he could trust. Because of this, the other Froakie attacked and injured him. During his time at the breeding facility as a Froakie, he preferred to train alone instead of socializing with his kind. Greninja seems to be a tough and strict Pokémon in reference to his personality. Greninja's troublesome past as a Froakie.
