Dear Maiko Iida,
Thank you for contacting us!
Please inform that Indonesian passport holders are granted 30-day-Vietnam visa exemption. Thus, if you will stay in the country less than 30 days, you do not need to apply a visa for Vietnam. Your passport is good enough.In the case, you will be in Vietnam more than 30 days, you will have to apply for Vietnam visa at Vietnam Embassy/Consulate in advance.