  We searched for precursive soft X-ray flashes (SXFs) associated with
optically-discovered classical or recurrent novae in the data of five-years
all-sky observations with
  Gas Slit Camera (GSC) of the Monitor of All-sky X-ray Image (MAXI). We first
developed a tool to measure fluxes of point sources by fitting the event
distribution with the model that incorporates the point-spread function
(PSF-fit) to minimize the potential contamination from nearby sources. Then we
applied the PSF-fit tool to 40 classical/recurrent novae that were discovered
in optical observations from 2009 August to 2014 August. We found no precursive
SXFs with significance above $3 \sigma$ level in the energy range of 2$-$4 keV
between $t_{d}-10$d and $t_{d}$, where $t_{d}$ is the date when each nova was
discovered. We obtained the upper limits for the bolometric luminosity of SXFs,
and compared them with the theoretical prediction and that observed for MAXI
J0158$-$744. This result could constrain the population of massive white dwarfs
with a mass of roughly 1.40 solar mass, or larger, in binary systems.
