Ryota Yamada serves as a military crew member aboard a Peace-Keeping Navy (PKN) submarine in the OVA series "Submarine 707R". He operates within the context of the PKN's naval warfare against the terrorist organization USR. His physical appearance is characterized by an overweight build, consistent with his character design. Information regarding his background, personal history, specific contributions to the plot, motivations, relationships, or character development within the narrative is not detailed in the original OVA episodes. His presence remains confined to this documented media.