Murō Saisei shares an exceptionally close bond with Hagiwara Sakutarō, characterized as a "two souls, one body" friendship. This intense connection points to deep emotional and spiritual interdependence. Their relationship unfolds through recollections, with one recollection carrying the strong implication that Hagiwara may have been canonically in love with Murō. This portrayal draws from historical accounts noting the real Hagiwara Sakutarō was homosexual and reportedly admitted to a brief romantic attachment to the real Murō Saisei. The dynamic between Murō and Hagiwara forms the entirety of Murō's character representation.