No problem! We’re happy you’re so interested in the game. <3
If you choose to side with Cain and get on Cain’s route, it’s true that you will likely alienate Akio to a certain extent, but that’s only because those two characters are directly opposed to each other. If you get on other character’s routes, you’ll have opportunities to interact positively with him still even if you’re not romancing him. Certain characters get along better with certain people than others, you know? So depending on the route you end up on, you’ll have different opportunities and different ways to interact with the other characters.