Kazuya is another of Tsukushi's childhood friends. After his family gains wealth through real estate transactions, he enrolls at Eitoku. The other students there make a clear distinction between Kazuya's "new money" and their own "old money." This difference is frequently pointed out by the F4 in particular.
Tsukushi feels relieved to have a friend at Eitoku but is concerned about Kazuya's safety if he continues to associate with her. She is especially worried about Domyoji, who clearly sees Kazuya as a romantic rival.
Kazuya is deeply loyal to Tsukushi and has romantic feelings for her, but he is also somewhat naive and not very perceptive. He does not appear in the drama adaptation.
(Source: Wikipedia)









