Tomoko has been Nanako's best friend and support since childhood. Because of Nanako's admission in the Sorority their relationship - and the trust Tomoko has in Nanako - will be affected negatively.

Differently from the manga, however, in the anime this rift, caused by some lies told by Mariko, will be resolved, and Tomoko will always be by Nanako's side, inciting and helping her as usual in her moments of despair or difficulty.

With the passing of time, Tomoko will also become friends with Mariko, and will defend her in front of the others more than once.

Tomoko's presence in the anime helps in giving a tone of "normality", and helps the viewer not to lose the contact with real life: while all the girls at Seiran base their lives on the Sorority's activities, making of them a matter of life and death , Tomoko always shines in her simplicity, letting the viewer breathe in relief... (from http://members.tripod.com/~aoisora)