Between the information gathered, it is possible to provide a comprehensive description of Nejiru Gaou from the anime D4 Princess. Nejiru Gaou is a Panzer and a second-year student at Teito Academy, where she is known by her fearsome moniker, Bloody Drill. Her physical appearance is distinctive, with green hair that falls to chest length and red eyes, fitting her image as a formidable teenager. Her name, which means to twist, directly correlates with her choice of weapon, a powerful drill she employs in battle.

Nejiru occupies a pivotal role in the story as the dream opponent of the protagonist, Doris Ruridou. From the moment of her first encounter with Doris on her first day at the academy, Nejiru is established as the benchmark of power that Doris aspires to meet. Her reputation among other Panzers is not necessarily built on technical skill but on overwhelming destructive power, making her a source of fear for her peers. This destructive capability defines her personality on the battlefield, presenting her as an intimidating and powerful force.

Despite this fearsome reputation, her motivations and deeper personality are revealed through her actions and key relationships. She accepts a challenge from Doris, leading to a match that ends in a draw, partly because Nejiru is described as being rusty after a long absence from fighting, and Doris has shown significant progress. This acceptance of a challenge from a less experienced fighter could be seen as a sign of her straightforward and perhaps honorable nature as a warrior.

A significant event in her development is a tragic accident. Nejiru is fatally injured while she and Doris are using their powers to rescue construction workers from a collapsing structure. This moment is critical for her character arc, as it is not a defeat in battle but an act of heroism that leads to her demise. Her death has a profound impact on the narrative, as Doris is overcome with guilt, believing she failed to save Nejiru from a slow death. This event serves as a major catalyst for Doris, who finds courage and solace in Nejiru's younger sister, Nejiri, and is driven to continue her path as a Panzer. The fact that Doris is the only person outside the Gaou family who remembers Nejiru further underscores the unique and significant bond they shared. Through this relationship and her ultimate sacrifice, Nejiru moves from being a simple rival to a key figure in the emotional development of the protagonist, highlighting her bravery and the lasting legacy she leaves behind.