Expected future growth of J1406 in the plane of the BH mass and host stellar mass, together with the distribution of z > 6 quasars compiled in T. Izumi et al. (2021) and those in the local Universe (J. Kormendy & L. C. Ho 2013), substituting dynamical/bulge mass for stellar mass. The current stellar mass and BH mass obtained from the SED fitting and spectral fitting, respectively, for J1406 is shown by the red star. The open star represents the BH mass of J1406 using the J. Kormendy & L. C. Ho (2013) scaling relation with the correction of redshift evolution following A. Merloni et al. (2010). The blue arrow indicates the growth of J1406 with a constant Eddington ratio of λ_Edd = 3 and radiation efficiency of η = 0.03 for 10⁷ yr. The future location in the plane will be above the local scaling relation of J. Kormendy & L. C. Ho (2013; black line) by a factor of a few, which is close to the scaling relation of the high-z massive quasars (blue dashed line; A. Pensabene et al. 2020).