Sorry, I don't understand the poly thing with MC, Barghest and Jason. I want to be mono from the very start. Can I? Or they were in a relationship like this? If so, then I can't play for something I find extremely unpleasant.
You can play the game however you want. Adriel, Barghest, Jason, and Grigori are the four love interests. The story is written as a single route so it honestly doesn't matter who you choose and there's an option to skip romance altogether if that's not your cup of tea, because it's a story about friendship as well. ♥ And if it makes you uncomfortable I won't be offended. Different people enjoy different things. ^^