We have initiated a Very Long Baseline Interferometer (VLBI) monitoring project of 36 methanol maser sources at 6.7 GHz using the Japanese VLBI Network (JVN) and East-Asian VLBI Network (EAVN), starting in August 2010. The purpose of this project is to systematically reveal 3-dimensional (3-D) kine- matics of rotating disks around forming high-mass protostars. As an initial result, we present proper mo- tion detections for two methanol maser sources showing an elliptical spatial morphology, G 002.53+00.19 and G 006.79-00.25, which could be the best candidates associated with the disk. The detected proper motions indicate a simple rotation in G 002.53+00.19 and rotation with expansion in G 006.79-00.25, respectively, on the basis of disk model fits with rotating and expanding components. The expanding motions might be caused by the magnetic-centrifugal wind on the disk.

We have initiated single-dish monitoring observations of 400 methanol maser sources at 6.7 GHz using the Hitachi 32-m radio telescope from December 2012 to systematically research periodic ux variations, which are observed in some methanol maser sources associated with high-mass (proto-)stars. In our monitoring, we have made daily monitoring, so that each source has been observed every nine days with an integration time of 5 min (typical 3  detection sensitivities of 0.9 Jy). The monitoring observations help us statistically understand periodic ux variations with a period longer than 50 days. As an initial result, we present a new detection of periodic ux variations in the 6.7 GHz methanol maser source G 036.70+00.09. The period of the ux variations is ~53 days (~0.019 cycles day-1), and seems to be stable over 9 cycles, at least until the middle of August 2014.