  In plane-wave matrix model, the membrane fuzzy sphere extended in the SO(3)
symmetric space is allowed to have periodic motion on a sub-plane in the SO(6)
symmetric space. We consider a background configuration composed of two such
fuzzy spheres moving on the same sub-plane and the one-loop quantum corrections
to it. The one-loop effective action describing the fuzzy sphere interaction is
computed up to the sub-leading order in the limit that the mean distance $r$
between two fuzzy spheres is very large. We show that the leading order
interaction is of the 1/r^7 type and thus the membrane fuzzy spheres
interpreted as giant gravitons really behave as gravitons.
