Imu, a third-year student at Hebijo Clandestine Girls' Academy and older sister to Murasaki, sports light brown hair in two side buns, dark green eyes, and glasses. Her signature shinobi attire features a military-inspired design: a green beret, a green coat decorated with black crosses and shoulder pads, a plated white skirt edged in red, black stockings ending just above the knees, and medium-length green boots bearing black cross patterns. Her undergarments and swimsuits typically follow a green camouflage theme, a fact that causes her embarrassment when brought up. Her past is defined by a deep childhood friendship with Miyabi. They frequently played shinobi together, culminating in a nighttime escapade where they stole their fathers' weapons and encountered a Yōma in a forest. Fleeing for their lives, Miyabi's mother intervened to protect them but was killed by the creature. This tragedy plunged Miyabi into prolonged mourning, and both girls swore an oath to eradicate all Yōmas. Miyabi's father subsequently trained them to become shinobi. At Hebijo Academy, Miyabi focused intensely on joining the elite squad, challenging Imu to pass a combat exam to remain by her side. Though Imu succeeded, she continued to feel inadequate in Miyabi's estimation. A pivotal elite mission involved ambushing a rival shinobi team hunting a Yōma. The operation failed disastrously when the Yōma exploited the chaos, killing all participants except Imu and Miyabi. Imu witnessed helplessly as allies and enemies perished, followed by Miyabi entering a berserk state to slay the Yōma. Miyabi then fell into a coma. Imu retired from active shinobi duties to support her recovery during hospitalization. After Miyabi awoke three years later, Imu assisted her and Rin in rebuilding the destroyed Hebijo Academy. Imu exhibits a naïve yet kind personality with distinct otaku tendencies, often referencing anime tropes. Her devotion to Miyabi borders on self-sacrificial; she prioritizes Miyabi's well-being above all else, including abandoning her shinobi career. She also strives to reconnect with Murasaki, whom she had neglected after family attention shifted to Murasaki's inherited "Root of Calamity" abilities. Imu persistently encourages Murasaki to leave her reclusive lifestyle, though her methods sometimes annoy her sister. Despite her generally calm demeanor, Imu reacts fiercely to threats against Miyabi, Murasaki, or Hebijo. She harbors a lasting grudge against Hikage for past harassment, including defacing her glasses with permanent marker, replacing her washcloth with deep-fried tofu, and swapping her computer mouse with a live rodent. In *Estival Versus*, she pursues revenge against Hikage for an incident where her boxer shorts were exposed publicly, earning her the nickname "Imu the Pro Boxer". In combat, Imu wields an extendable Bo staff capable of altering its length and thickness. She employs shock effects to paralyze opponents and excels in close-quarters combat with rapid combos and aerial techniques. Her Ninja Arts unleash wide area-of-effect attacks effective against groups. A critical moment occurs when Ryōbi shoots Murasaki during a confrontation, triggering Imu to awaken her latent "Root of Calamity" power to defeat Ryōna and Ryōbi. Rin later intervenes to reveal the truth behind Ryōki's death, leading Imu to forgive the sisters and accept them into Hebijo's reformed team. In *Peach Beach Splash*, Imu appears outdoors with her team, featuring Murasaki napping on her lap, signaling their improved relationship. She participates in the tournament after receiving an invitation.