Your Sun Sign is your core self -- what makes you distinctly you at a very basic level. Where the Sun lies in your birth chart directly influences your self-confidence and self-awareness, your strengths and ambitions and much, much more. The two of you have no aspects between your Suns, which means that on a basic level, you're not at all alike.
If you're going to be friends, it won't be based on a feeling of familiarity or commonality! But hey -- if you tend to be attracted to people precisely because they're new and different from what you're used to, this could work. If you maintain your friendship, this probably indicates that your charts will have a lot of other points of contact to draw you together. Other areas of your relationship will take more of the focus and importance than being matched up in your personalities.