  Although the LHC experiments have searched for and excluded many proposed new
particles up to masses close to 1 TeV, there are many scenarios that are
difficult to address at a hadron collider. This talk will review a number of
these scenarios and present the expectations for searches at an
electron-positron collider such as the International Linear Collider. The cases
discussed include the light Higgsino, the stau lepton in the coannihilation
region relevant to dark matter, and heavy vector bosons coupling to the
s-channel in e$^+$e$^-$ annihilation. The studies are based on the ILD concept
at the ILC.
