  The inclusive cross sections for di-hadrons of charged pions and kaons
($e^+e^- \rightarrow hhX$) in electron-positron annihilation are reported. They
are obtained as a function of the total fractional energy and invariant mass
for any di-hadron combination in the same hemisphere as defined by the thrust
event-shape variable and its axis. Since same-hemisphere di-hadrons can be
assumed to originate predominantly from the same initial parton, di-hadron
fragmentation functions are probed. These di-hadron fragmentation functions are
needed as an unpolarized baseline in order to quantitatively understand related
spin-dependent measurements in other processes and to apply them to the
extraction of quark transversity distribution functions in the nucleon. The
di-hadron cross sections are obtained from a $655\,{\rm fb}^{-1}$ data sample
collected at or near the $\Upsilon(4S)$ resonance with the Belle detector at
the KEKB asymmetric-energy $e^+ e^-$ collider.
