  In this paper, we provide a correspondence between certain 5-dimensional
complex spacetimes and 4-dimensional twistor spaces. The spacetimes are almost
contact manifolds whose curvature tensor satisfies certain conditions. By using
the correspondence, we show that a 5-dimensional K-contact manifold can be
obtained from the Ren-Wang twistor space, which is obtained from two copies of
\C^4 identifying open subsets by a holomorphic map. From this result, the
Ren-Wang twistor space can be interpreted in the framework of Itoh.
