Japan’s summer holiday season moved into full swing on Saturday, with people heading to their hometowns amid caution as the weather agency issued an advisory over a potential megaquake. “It is my first visit to my hometown in five years after a hiatus due to the coronavirus. Now it is an earthquake,” Tomohiro Ogawa, 49, a resident of Chiba Prefecture, said at a packed JR Tokyo Station, adding he has discussed preparing for a disaster following the alert with his family. On Thursday, the Japan Meteorological Agency issued its first-ever advisory on a potential megaquake in the Nankai Trough, wh…