Mikoto Bōida, a high school student and Haruto Bōida’s younger sister, shares an unshakable bond with her brother forged through childhood viewings of the anime *Shōjo⇒Wakusei Tansa* (Girl⇒Planetary Probe). Like Haruto, she developed a lasting admiration for the character Ozma, their shared enthusiasm anchoring her connection to the series.

Her inquisitive nature drives her to investigate the inexplicable sentience of figurines, sparked by encountering Nona—a 1/6-scale animated replica of the anime’s heroine—at Haruto’s home. Repeated attempts to unravel the mystery yield no answers, yet the unsolved enigma only intensifies her visits, drawing her deeper into Haruto’s peculiar world.

During exchanges with Nona, Mikoto probes the figure’s perspective on her relationship with Haruto, blending methodical analysis with empathy. Nona’s fragmented grasp of human emotions, however, leaves their dialogues unresolved. Undeterred, Mikoto persists, balancing curiosity with a desire to mediate their unconventional dynamic.

Her surname, Bōida (房伊田), weaves the characters for "chamber," "that one," and "field"—a subtle nod to her roots. While family ties and shared passions define her background, her story centers on observing and dissecting the supernatural phenomena entwining Haruto and the living figures, positioning her as both witness and sleuth in their unfolding mystery.