An extremely attractive woman as well as an expert combatant (she carries a shikomizue in her walking cane and is highly adept at shurikenjutsu), Kagerou's sensuality is her deadliest weapon as her breath becomes poisonous when she's sexually aroused. According to the Kouga, it is an ability shared by all women in her family.
NOTE: The shikomizue (literally "prepared cane") is a Japanese concealed sword disguised as a cane or walking stick, similar to the swordstick. It was used mostly by the Shinobi. It is most famous for its use by the fictional swordmaster Zatoichi.
She's deeply and madly in love with her superior and cousin Kouga Gennosuke. But due to Gennosuke's feelings for Oboro and her own technique, she's unable to be with him either emotionally or physically; resulting in a jaded persona filled with envy and bitterness.
Kagerou's favorite target for her frustrations is Oboro and was one of the more vocal opponents of Oboro and Gennosuke's marriage, being quick to belittle and criticize Oboro every chance she could which usually results in her receiving a firm reprimand from Muroga Hyouma.
Noticing how extreme Kagerou's conduct was becoming, Gennosuke's grandfather Danjo had discussed with Hyouma before setting out for Sunpu that perhaps it was time to find a man for Kagerou to have a child with. Despite Kisaragi Saemon's doubt of that ever happening, Hyouma revealed that there were actually several men in Kouga willing to sacrifice all for one night of pleasure with her.
When the Kouga finally learn that the Hattori truce had indeed been absolved, few were happier about the news than Kagerou who saw it as an opportunity to seek revenge on Oboro for taking what (who) Kagerou felt should have rightfully been hers.