Heres a translation of the conversation between Satoshi and Jun (The scene after beating Team Rocket and parting ways with Melissa)
Jun: I see, you and Melissa-san are going to battle.
Satoshi: Yeah, your going to challenge her again right?
Jun: Of course! If i can't beat her with my Emperte, i'll look for stronger pokemon and get them. And if not, i'll look for more. That way, no matter what gym leader you face, you can't lose, right?
Satoshi: Is that so... Just because you find strong pokemon doesn't mean you'll always win.
Jun: huh?
Satoshi: You have to think about your Pokemons skills and character and you have to train together and fight as one heart. Isn't that the most important?
Jun: Character, skills, heart?
Satoshi: Even if your weak right now, if you work hard, eventually you'll get strong. That's what I believe.
Jun: ”Eventually” is no good. You see, I wanna get strong fast. Overall, I wanna get strong, like Shinji!
Satoshi: Shinji...
*flashback*
That guy...
Jun: Shinji's so cool right? Don't you think so? Huh? Huh? Hey, what's wrong?
Hikari: Satoshi has battled Shinji before...
Jun: Battle!? With Shinji!? And then what? Did you win? Lose?
Satoshi: ...
Jun: Ah, I see, you definitely lost! Afterall, your opponent was Shinji, so it can't be helped...
Satoshi: What did you say!?