prtib answered your question:Gaim question: Why hasn't Kouta given his Genesis Core to Kaito?
Because Kouta doesn’t think ahead and Kaito would never ask.
That's a fairly good point. I think the only way Kouta would realize "Hey! You could use this too!" would be if Kaito's Genesis Driver was broken or lost and he had to strictly use the Sengoku Driver from that point on.












