Tomoya is a good guy who knows how to fight when needed but Obi is a trained professional. He will be able to get the win rather easily with or without a weapon. When you have two characters without any special abilities, the trained fighter will win 9 times out of 10. There just isn’t anything Tomoya can do to try and turn the tides of battle. Obi (Snow White) wins.
Obi (Snow White) vs Tomoya Okazaki