Kanae wants Kazuki to make her his lover so much that it kind of became an obsession for her. She affectionately calls him Nii-sama however all her attempts are useless since Kazuki sees her only as his little sister. However, unknown for her, Kazuki sees her not like a little sister, but as a member of the opposite sex as stated in Volume 6. In Volume 9 Kazuki recognizes Kanae as a woman and kissed her.
Kanae seems often has arguments with Kaguya, but in truth she likes her and respects her for her strength.