  We have analyzed all the archival X-ray data of 134 unidentified (unID)
gammaray sources listed in the first Fermi/LAT (1FGL) catalog and subsequently
followed up by Swift/XRT. We constructed the spectral energy distributions
(SEDs) from radio to gamma-rays for each X-ray source detected, and tried to
pick up unique objects that display anomalous spectral signatures. In these
analysis, we target all the 1FGL unID sources, using updated data from the
second Fermi/LAT (2FGL) catalog on their LAT position and spectra. We found
several potentially interesting objects, particularly three sources, 1FGL
J0022.2-1850, 1FGL J0038.0+1236 and 1FGL J0157.0-5259, which were then more
deeply observed with Suzaku as a part of an AO7 program in 2012. We
successfully detected an X-ray counterpart for each source whose X-ray spectra
were well fitted by a single power-law function. The positional coincidence
with a bright radio counterpart (currently identified as AGN) in the 2FGL error
circles suggests these are definitely the X-ray emission from the same AGN, but
their SEDs show a wide variety of behavior. In particular, the SED of 1FGL
J0038.0+1236 is difficult to be explained by conventional emission models of
blazars. The source 1FGL J0022.2-1850 may be in a transition state between a
low-frequency peaked BL Lac and a high-frequency peaked BL Lac object, and 1FGL
J0157.0-5259 could be a rare kind of extreme blazar. We discuss the possible
nature of these three sources observed with Suzaku, together with the X-ray
identification results and SEDs of all 134 sources observed with Swift/XRT.
