We have investigated the coarsening process of domains having a cubic lattice in a nonionic surfactant system using a time-resolved small-angle neutron scattering technique. The obtained time evolution of scattering patterns showed growing large domains with strong diffraction intensity fluctuation and shrinking small domains obeying dynamical scaling law. This bimodal domain coarsening suggests an anomalous domain coarsening. During the coarsening the cubic lattice was distorted about 10%, which is probably due to the adjustment of the adjacent lattice at boundary. This elasticity effect probably brings about the observed anomalous domain coarsening.