Shiro is a white dragon companion journeying with Pastel's party of adventurers. Alongside members like Clay the Warrior, Trap the Thief, Rumi the Elf, Kitton the Learner, and Knoll the Giant, Shiro joins quests ranging from simple tasks such as retrieving hot spring water to confronting world-threatening dangers, all driven by the group's financial struggles.

Physically, Shiro resembles a small, cute canine-like creature. This design predates and shares a visual similarity with Nall from *Lunar Silver Star*, embodying elements reminiscent of classic tabletop role-playing games that contribute to the series' fantasy atmosphere.

Shiro's narrative spans multiple light novel arcs, directly referenced in titles like *Shiroi Ryuu ni Hirai Shita Machi* (The Town That Opened to the White Dragon) and *Shiro-chan to Inishie no Monster* (Shiro-chan and the Ancient Monster). These stories explore the dragon's connections to ancient creatures and mythical settings, reinforcing Shiro's role within the adventuring framework.

As a non-human party member, Shiro provides support during missions. Specific abilities or combat contributions remain undocumented, but the character is a consistent presence throughout the party's journeys, including their adaptation from light novels into a four-episode OVA anime.