Japan has issued its first-ever 'megaquake advisory' following a 7.1-magnitude earthquake off the southern coast, warning of a possible major earthquake from the Nankai Trough. Prime Minister Fumio Kishida canceled his Central Asia trip to manage the crisis, emphasizing the importance of preparedness. The advisory has caused public panic, leading to hoarding of supplies and shortages in stores. Authorities urged residents to stay calm and follow guidelines, while bullet trains have reduced speeds and nuclear plants double-check their disaster protocols. The advisory aims to raise awareness and preparedness, although it does not guarantee that a megaquake will occur. Local governments and agencies have started precautionary measures, impacting holiday travel and activities.