I think the best path for Ryou's character to take would be some form of him taking his own path, away from Yukki. Ryou's entire life has revolved around Yukki and trying to copy her lifestyle and path in life to get closer to her. All this has resulted in Yukki never seeing him as anything more than a friend, and one that she finds irritating at times. Even Ryou's attempt to get closer to Yukki backfired severely and only served to emphasize the difference between how Yukki sees Ryou and how Yukki see Shindou. At this point in the story, I don't think it would make logical sense for Ryou and Yukki to get together romantically, outside of fulfilling the "pair the spares" trope.
Either Ryou needs to go to a different university than Yukki, or even something as drastic as not go to college all together and either do a labor type job or backpack across the country/world. What Ryou needs right now is not having his romantic feelings be reciprocated. What Ryou truly needs is to find out what kind of person he is outside his relationship with Yukki. In other words, Ryou needs to discover his own identity, to find himself.