Makoto Shido is a central female mountain bike rider in the series, characterized by brown eyes and black hair worn in a hip-length ponytail. Her signature outfit includes a black tank top layered under a purple denim jacket, a matching purple skirt, pink rubber shoes, and accessories like a hair ribbon and gloves.

Personality-wise, she balances kindness, helpfulness, and sensitivity with occasional moodiness and temper outbursts, always seeking to make amends afterward. Her determination intensifies when fully dedicated to objectives. She maintains a close childhood bond with Sho Yamato and Kakeru Sakamaki, attending their school. Her brother Kyoichi Shido serves as her ultimate role model; she deeply admires him and strives to mirror his biking prowess and character. Kyoichi taught her cycling and gifted her mountain bike Neptune, later revealed as a legendary water-powered Idaten Bike identified by its gold emblem post-cleaning.

Her journey initiates when transported alongside Sho and Kakeru to the X-Zone during a race against the Samejima brothers. There, she competes in Idaten Battles across volcanic, ruinous, desert, and snowy mountain terrains to gather emblems for returning home. She manages practical group duties like cooking, cleaning, and transport truck maintenance, while indulging her fondness for sweet treats—especially chocolate sundaes and junk food.

Kyoichi’s influence drives pivotal arcs. Unaware of his X-Zone presence initially, she reunites with him only to discover he hides their sibling tie to shield her as Team X’s leader. Persistent despite others’ resistance, she probes for information fueled by profound concern. When a dark emblem corrupts Kyoichi, he imprisons her in a cellar. During a lucid interval, he etches an escape plan onto a window using moonlight. With Gabu Samejima, she retrieves their Idaten Bikes, thwarts Kyoichi’s trap mid-race, and directly enables his rescue and liberation from the dark emblem.

Her dynamic with Sho features a duel-race partnership and habitual care for his well-being, though extreme anger sometimes triggers quarrels. She harbors romantic feelings for him and weeps first during their farewell. In critical battles, she unleashes Neptune’s powers to safeguard Sho’s platinum emblem after his Flame Kaiser bike sustains damage. She also mediates conflicts, notably reconciling the Four Kings and Gabu Samejima by urging unity against Team X.