Hirohiko Yokomi stems from real-life accomplishments, having documented his completion of all JR stations in Japan by 1995 before achieving nationwide coverage of all 9,843 stations by 2005. This feat established the foundation for a manga where he anchors travel narratives.

He embodies a dedicated railway enthusiast possessing exhaustive knowledge of Japan's train systems. His meticulous planning manifests in micromanaged itineraries timed to the second, prioritizing schedule adherence above other considerations. This includes devising intricate station-sequencing strategies to align with infrequent services and engineering challenges such as traversing six rural regions around Tokyo using a single 130-yen ticket.

During documented journeys, he operates as the de facto leader, frequently overlooking companions' preferences or fatigue. His focus centers solely on logistical milestones over experiential enjoyment, approaching stations as checklist entries rather than leisure destinations. This methodology generates recurring friction with the accompanying manga artist, who exhibits overt disinterest in railway culture.

Throughout manga iterations—the original series (2001-2006), sequel "Shin Tetsuko no Tabi" (2009-2013), and "Tetsuko no Tabi 3-daime" (2016-2019)—his role persists unchanged. He consistently guides distinct illustrators across series, upholding his persona as an uncompromising railway specialist devoted exclusively to station-visiting objectives. Official adaptations introduce no substantive personal evolution or expanded backstory beyond this core depiction.

Publisher Shogakukan acknowledged his real-life recognition as the "ultimate railway otaku" and his contributions to promoting Japanese railway culture through these works following his death in 2025.