Kusunoki comes from a prestigious martial arts family, where she has been rigorously trained since childhood to inherit the Kasuga-Style Life and Death Technique. As a result, she has grown up believing that strength must come above all else, rejecting anything that might distract her from her martial arts training, including romantic feelings and femininity.

At Maijima Private High School, she is the only member of the Women’s Martial Arts Club, as no other girls are willing to endure her strict and demanding training regimen. Due to her strong and intimidating presence, she is often feared or misunderstood by her peers, further isolating her from normal high school interactions.

Despite her tough exterior, Kusunoki secretly longs for feminine experiences, such as wearing cute clothes and embracing her softer side. However, she sees these desires as weaknesses and tries to suppress them until Keima’s intervention forces her to face her true self.

Kusunoki has an athletic and toned physique, reflecting her martial arts training and disciplined lifestyle. She has sharp, dark blue eyes and long black hair tied in a high ponytail, giving her a strong and commanding presence.

She is most often seen wearing a black martial arts gi, a sign of her dedication to training. However, during her conquest arc, she is reluctantly forced into more feminine clothing, showcasing her hidden desire for self-expression and adding to her internal conflict.

Kusunoki is strict, disciplined, and extremely focused on her martial arts training, often appearing cold and distant toward others. She values strength above all else and has little patience for weakness, distractions, or unnecessary emotions.

Despite her tough and serious nature, Kusunoki struggles with internal contradictions. Deep down, she has a feminine side that she suppresses, believing that it contradicts her martial arts philosophy. This internal battle creates conflict between her duty as a martial artist and her personal desires, leading to moments of self-doubt and frustration.

Keima’s conquest reveals that Kusunoki is not emotionless she simply doesn’t know how to balance her responsibilities with her emotions. Over time, she learns to accept that strength and femininity can coexist, allowing her to embrace her full self without abandoning her martial arts.

• The Conquest of Kusunoki Kasuga
  Keima’s conquest begins when he notices Kusunoki acting strangely, seemingly struggling with an invisible force. It is soon revealed that a runaway spirit has manifested as a spiritual projection of Kusunoki’s feminine side, taking the form of a softer, more delicate version of herself. Kusunoki is horrified by this manifestation, believing it to be a weakness that threatens her discipline. However, Keima realizes that this spirit represents her repressed emotions and desires, forcing Kusunoki to confront the side of herself she has long denied. Throughout the conquest, Keima challenges Kusunoki’s rigid views on strength, showing her that embracing femininity does not mean losing power. As she slowly comes to terms with her true feelings, the runaway spirit weakens, ultimately leading to Kusunoki accepting her dual nature and successfully expelling the spirit.

• Post-Conquest and Character Growth
  After her conquest, Kusunoki begins to change, allowing herself to express emotions more freely while still maintaining her martial arts training. Though she remains disciplined and focused, she no longer views femininity as a weakness, demonstrating a more balanced and self-assured personality. Her development continues in later arcs, where she becomes a valuable ally to Keima, offering physical strength and martial expertise in key moments. Though she does not actively pursue romance, she develops a quiet respect for Keima, acknowledging his wisdom in helping her grow as a person.