Wait I don’t have the game. Will it be cool for you to explain 😅
Mamechin (nickname for Fenomeno) and Justa (short for Just A Way) are both yet-to-be-implemented horses that are not just contemporaries to Gold Ship, but the former is Golshi's rival and the latter is his stablemates/BFF.
Since they're both contemporaries to Golshi (and 'Donna et al), the two would make for some wild generational pairing, much like the 97 (Suzu, Taiki, Dober) or 98 gens.