  It has been a long-standing problem to detect interstellar glycine
(NH$_2$CH$_2$COOH), the simplest amino acid, in studying a possible relation
between the Universe and origin of life. In the last about 40 years all surveys
of glycine failed, and it would be an alternative strategy to search for
precursor(s) to glycine. Such studies of precursors would be crucial prior to
conducting sensitive surveys by ALMA.
  Laboratory studies have suggested that CH$_3$NH$_2$ is a possible precursor
to glycine. Further theoretical study also suggested that the CH$_2$NH$_2$
radical that can be formed from CH$_3$NH$_2$ through photodissociation can be a
good precursor to glycine. Thus we observed CH$_3$NH$_2$ towards several hot
core sources by using the Nobeyama 45m radio telescope, and succeeded in
finding a new CH$_3$NH$_2$ source, G10.47+0.03, with its fractional abundance
of 2.4+-0.6x10^{-8}; at the time of writing, this source is the most abundant
source of CH$_3$NH$_2$ ever known. We also found another new source of
CH$_3$NH$_2$, NGC6334F, however, the detection may be tentative since the
signal-to-noise ratios are not sufficient to claim secure detection. Detailed
analysis of the detected data revealed the detection of the hyperfine
components of CH$_3$NH$_2$ for the first time. We found that the observed
abundance of CH$_3$NH$_2$ agrees fairly well with the theoretically predicted
value by Garrod (2013). Detectability of interstellar glycine is discussed.
