Miko Bido is the central heroine of the adult anime series La Blue Girl. She is a teenage kunoichi, or female ninja, and the final living descendant of the Miroku ninja clan, a lineage that has been locked in a generations‑long conflict with the rival Suzuka clan. Her parentage is remarkable: she is the daughter of Seikima, the king of the demonic Shikima race, and Maria, a human woman who was once a member of the Miroku clan. This hybrid heritage gives Miko blue‑colored blood, which is the reason she is known as the La Blue Girl. She was raised by her grandmother, who trained her in the ways of the ninja before passing away before the events of the story.

In terms of personality, Miko is typically depicted as a cute, cheerful, and easy‑going young woman. She possesses a strong will and resilience, enabling her to face the many demonic threats that arise throughout the series. Despite her pleasant demeanour, she is often irritated by the reality of her role as a sex ninja, forced to use her own body and intimate techniques as weapons against opponents. She is also shown to be dedicated to her academic studies, though her specific grades remain unclear.

Miko’s primary motivation is to protect the human world and uphold the pact between her clan and the Shikima demons. Her journey begins when a stolen magical compact, which symbolizes the truce between the Miroku and the Shikima, throws the balance into chaos. She must employ the unique sexual combat arts of the Miroku clan to survive and restore order. Over the course of the original OVA series and its sequels, she learns the truth about her demonic father and human mother, fully embracing her destiny as the next leader of the Miroku. In later installments such as La Blue Girl EX and La Blue Girl Returns, she faces new adversaries, including vengeful ghosts and the insect‑like Mahoroba clan, while continuing to protect her younger sister, Miyu Bido, and her allies.

Key relationships in Miko’s life include her father Seikima and her mother Maria, who appear in the Shikima realm. Her grandmother, who raised her, is deceased. She works alongside a ninja companion often referred to as Nin‑Nin or Fubuki, and she also shares a close bond with her sister Miyu. In the EX series, she develops a first love with a young man named Hidemasa, whose kidnapping by a phantom draws her into a deeper investigation of a centuries‑old curse.

Miko’s notable abilities are drawn from the Miroku clan’s specialized sexcraft ninjutsu. She can harden her pubic hair into sharp needles and launch them at enemies, and she can use strands of her own hair as acupuncture needles to stimulate an opponent’s pleasure points. Another technique, known as Nyoninboh, allows her to swell her clitoris to the size of a male organ, which she can use to drive female rivals into a frenzy. Her most powerful and visually striking attack is the Aoi Tatsumaki, or Blue Whirlwind, in which her hair transforms into a massive blue tornado that typically tears away her clothing. Additionally, she possesses considerable skill in music, which is referenced as an area of high proficiency in some sources. Throughout her adventures, Miko carries the magical compact that controls the Shikima, a key item that often becomes the target of her enemies.