When I was tagging and annotating the characters in this image, I used the Pokémon Mezastar characters page on Bulbagarden Archives to help me identify everyone. The two characters in the middle of the top row were labeled "Senior Trainers," so I tagged them as such. However, I later noticed that they bear a striking resemblance to the protagonists of Mezastar's predecessor, Pokémon Ga-Olé.

For reference:

• Male protagonist (Ga-Olé)
• Male senior trainer (Mezastar)
• Female protagonist (Ga-Olé)
• Female senior trainer (Mezastar)

I assume they're meant to be the same characters, but between how obscure these games are and the fact I don't speak Japanese, I can't confirm if they actually are or not. I'm keeping their tags separate just in case, but if anyone more knowledgable than me can prove they're the same, feel free to update their tags and notes to Female Protagonist (Pokemon Ga-Ole) and Male Protagonist (Pokemon Ga-Ole).