Yosuke, identified as "Grandson" in production materials for the OVA and 2012 television series, is grandson to the central character, an elderly man focused on teaching survival lessons. He attends school, where the Principal is a notable figure. Yosuke appears consistently across all franchise iterations: the original manga series published in CoroCoro Comic from October 2001 to March 2010, the subsequent manga series running from April 2010 to February 2017, the 51-episode anime television series broadcast on TV Tokyo from April 2004 to March 2005, the two-episode original video animation released in 2012, and the 2012 anime television series.