Touga immediately recognizes Utena when she first comes to the academy. He is impressed by her mental and emotional strength, as well as her radiant beauty, and tries to woo her over to him with gifts and his charm. She, however, does not give in that easily. Touga finds her weakness - her prince - and exploits it for his own use. He tells her that he is her prince, causing Utena to lose to him in a duel. Utena does come back though, and defeats him in a duel again. Touga does not appreciate being beaten by a girl, and goes into a state of depression. After he snaps out of it, Akio and Touga are constantly at odds with each other over the "possession" of Utena. They try to impress her with gifts, and battle to see who gives her the better one. Finally, Touga brings Utena up to the dueling arena to watch the stars. There, he confesses that he is in love with her, but is taken aback when Utena doesn't return the favor. He duels her one last time, but loses again. Utena changed Touga's life to the extremes.
Anthy could be seen as one of the first people to open Touga up. On his birthday, Anthy presents Touga with a small kitten. Touga allows himself to be loving to the cat and lets it crawl all over him. His guard has been left down, and he, for the first time, appears to be happy at something other than his rendezvous with girls. Touga possesses Anthy once during the series. He uses her to pour tea at student council meetings. They seem to understand eachother, even though they do not express it outwardly.
Touga's "best friend", is the kendo master Saionji. Touga and he had been friends since they were children, oftentimes riding their bikes together and practicing kendo. However, the fateful day that they found that coffin, Touga and Saionji went their seperate ways. Saionji, confused, decides to forget what he saw; but Touga was on a quest to find out what was going on. Touga, in essence, gets Saionji kicked out of the academy. He instigates a fire in Saionji that makes him want to duel Utena without permission. Touga then displays his frivolousness of the friendship by throwing Saionji and Anthy's exchange diary into an incerator. When Akio comes into the picture, Saionji decides that he does not believe in anything eternal, but is forced into going to see the Ends of the World with Touga and Akio. Saionji and Touga make ammends for a little while, so that Saionji could be Touga's rose bride during his duel with Utena. When Utena leaves the academy, Touga and Saionji rebuild their bond as friends, and seemingly forget the infamous statement that Touga once made: "Only a fool believes he has friends."
Nanami, Touga's younger sister, has a real "brother-sister complex" with Touga. She will do anything for him (including going to India to get curry), and she does not let any girl get near Touga. If they do, she gets extremely defensive and proceeds to yell at, slap, plot against, etc. For instance, when Anthy gave Touga the kitten, Nanami got wildly jealous; and when Touga spent lots of time watching Utena, Nanami tried to plot against her. Touga finds this very ammusing, and never tries to stop her. One day, Nanami is looking up information on blood types (in Japan, blood type is said to determine one's personality). When Touga will not tell her his blood type, Nanami becomes suspicious. She finally comes to the conclusion that Touga and her are not real brother and sister, and Touga, adding to the fire, will not confirm or deny it to her. "It's more romantic to be a brother that isn't tied to her by blood," he claims. In the end, Touga finally reveals to her that they were both adopted by the Kiryuu family together.
As two fellow student council members, Juri and Miki share a reverence and respect of Touga. They often times disagree with his methods of thinking, however. Touga also uses his mind-contol skills on Miki, but not on Juri. Surprisingly, there is not much interaction between Juri, Miki, and Touga during the series.
It was inevitable that Akio and Touga would form an alliance. Both of the men are suave, controlling, and have a great pressence. Akio brought Touga out of his depression after losing to Utena, and would drive him around in the Akio car. Touga is the one who knows the most about the Ends of the World. Akio and Touga are partners in crime in the beginning, but towards the end of their alliance, you can see a small rebellion in Touga towards Akio. Akio and Touga fight over the love of Utena, and Touga is forced to give a present from Akio to Utena. He begins to disagree with the methods of the Revolution, but he never outwardly rebels. Akio corrupts Touga, just like he did to everyone. And, they slept together.