The documented materials for *Gense Shugoshin P-hyoro Ikka* exclusively identify the Shinohara siblings—Kota, Qta, Kyota, and Ryoko—as the central characters. No character named "Ryū" appears within the verifiable details of the OVA's episodes, production information, or associated discussions. Official sources, including plot summaries, character listings, and staff credits, contain no reference to this name. Furthermore, no spin-offs, movies, or related media expanding the character roster beyond the established siblings are cited. Therefore, the response remains: **no info**.