  The production of a kaon pair ($K^+ K^-$ and $K^0_S K^0_S$) in two-photon
processes has been measured using the Belle detector at the electron-positron
collider KEKB. We have obtained the invariant-mass distribution of the
processes between 1.3 and 2.3 GeV. A broad bump structure around 1.7 GeV in the
$K^0_S K^0_S$ channel is confirmed, while, in the $K^+ K^-$ channel, a bump
structure is seen near 1.9 GeV. The angular distribution of the final-state
kaons is analyzed to explore the spin(-helicity) structure in each
invariant-mass region for the two processes. Contributions from existing and
postulated resonances are discussed.
