  SDSS J1430+2303 has been argued to possess a supermassive black hole binary
which is predicted to merge within a few months or three years from January
2022. We conducted follow-up optical spectroscopic observations of SDSS
J1430+2303 with KOOLS-IFU on Seimei Telescope in May, June, and July 2022, and
April 2023. The observed spectrum around $\mathrm{H}\mathrm{\alpha}$ shows a
central broad component $\sim 10^3\ \mathrm{km\ s^{-1}}$ blueshifted from the
narrow H$\mathrm{\alpha}$ line as well as the broader double-peaked component
with a separation of $\sim\pm 5\times10^3\ \mathrm{km\ s^{-1}}$, similar to the
spectrum reported in January 2022. We investigate the variability of the
complex broad $\mathrm{H}\mathrm{\alpha}$ emission line relative to the
continuum over the observation period. The continuum-normalized relative flux
of the central broad component shows the increasing trend from May to July 2022
which is interpreted to be caused by the decrease of the continuum as also
supported by damping of the X-ray, UV, and optical light curves observed for
the same period. From July 2022 to April 2023, however, the central broad
component decreased significantly. For the relative flux of the broader
double-peaked component, on the other hand, no significant change appears at
any epoch. These results suggest that the complicated broad line profile of
SDSS J1430+2303 is generated from at least two distinct regions. While the
central broad component originates from a broad line region, the broader
double-peaked component arises in the vicinity of the continuum source.
