I call him “Spica’s trainer” but as it turns out, JP fans have a name for him that has been taken as the unofficial one.
For those that don’t know, the first (and second) season of the anime has the “trainer”, the role that the player takes in the game, be inhabited by quite the recognizable guy. Instead of the usual “mild, short black hair, unassuming but kind guy” that most adaptations would take as the faceless player character, Spica’s trainer has a fade and a ponytail, he has a discernible attitude, really the only thing that he lacks is a proper name…
…or does he?
During an interview where Megumi Toyoguchi (Trainer Hana) and Koji Okino (Spica’s trainer) participated, Okino revealed that his character’s name was said to be “Ryo Nishizaki” (西崎リョウ) in a script, though this name was never officially used and even the anime only credits him as “Trainer”.
But with the advent of other spin offs and thus more actual named trainers outside of Rigil’s Hana, like Kitahara and Musaka (Cinderella Gray), Tsubaki (Star Blossom), Aoi and Riko-chan (the game), and more recently Okita (Road to the Top), fans have taken to calling Spica’s trainer “Okino T”, based on his seiyuu’s name.
By the way, Canopus’ trainer is named Minamizaka and Bourbon’s trainer is called Kuronuma.
Here’s the fun part though, Satomi Akasaka (who voices Misato Akasaka, the female race announcer) did refer to the character as “Okino Trainer” in the 4th Live, so while it’s still not official until it shows up in some credit, at the very least even the staff has acknowledged that name as “the best we have until proven otherwise”…
…which is how any of the Spica girls would describe Okino, fittingly enough.