Rider
Rider watched with some amusement as Oka began to perform a spookily-accurate impersonation of one of Rin's lectures, even down to the smart-looking glasses that Rider was sure Rin wore solely for show.
"Well, you see, you keep pokemon in pokeballs, like this one", Oka said, pulling out a small green, white and yellow ball.
Is that like Sakura's shadow dimension or something? Rider wondered, well aware of the size difference between the ball and the Pokemon that supposedly went inside it.
"This one is an ultra ball, but that doesn't matter, they all work the same. You keep pokemon inside them, and release them like this", the girl continued, before pressing the button on the middle of the ball and throwing it up in the air.
As soon as she had done so, the ball released a beam of light, which quickly turned into a large, ball-like purple creature. As it appeared, it began to laugh, drawing a reaction from Oka.
"Sh-shut up, they're cool!" the girl said, obviously somewhat embarrassed by his laughter.
"I see", Rider responded, trying not to laugh at the display and the rather-silly glasses. "Do they not mind being kept inside such a small ball?"