Ryu holds the 7th position in school, although his test scores are a poor reflection of his intellectual prowess. He is in 7th place mainly because of the twins - Megumi tends to fall asleep and Jun becomes bored during tests, which results in Ryuu focusing his attention on them instead of his own exam. This is proven in an anime episode, when he answers 1000 questions in 10 minutes, and manages to achieve full marks. He has been close to Megumi and Jun since they were very young; it is evident that he cares for the twins very much and that the three of them see each other as of the CEO of a sports company and one of his family.
He is very close with the twins and often takes care of them in their parents absence. They are also the main reasons why he is ranked 7th because Megumi tries to fall asleep and Jun becomes bored during the test which results in Ryuu focusing part of his attention on the twins rather than of his own exam. Although he doesn't mind this at all. The twins often fight over Ryuu especially when animals get his attention. He is actually very protective of them and is often seen resting with them or cooking their meals.