You can get in contact with the institution calling the following number (62-21) 324308 or visit the Consulate-General at Menara Thamrin Bldg, Jl. M. H Thamrin, Kav.3 Jakarta Pusat yourself. If you want to omit the visit to the Embassy, simply apply for a Japan e-Visa online. Fill the application form within minutes from home.
Visa to JapanJapan Electronic Travel Authorization