Even a Japanese panics in a disaster and feels lack of evacuation information especially when the disaster is large or hits at night. It is even more so for a world talent in Japan with limited information in native language available to know what happens and what to do for safety.
Evacuation information is provided typically by local governments, some of which are available in multiple languages. For example, Tokyo local government has a disaster evacuation site which can be machine translated into 9 languages.
Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has released an overarching site (“portal”) with links to major evacuation information sites across Japan. It is provided in 4 languages (English, Korean, Simplified and Traditional Chinese) in addition to Japanese. It should be noted however that some of the sites covered in the portal are still in Japanese only, even though the MLIT portal site itself is multi lingual. The portal is released as preparation to assist visitors for the 2020 Tokyo Olympic. I would hope it would be continued even after the game, as there is no other similar site available.
It is recommended that this kind of evacuation sites should be looked upon in advance, before encountering a disaster. So that you can pick up relevant sites and mark their URLs in your favorite for quick access.
It should be even better to keep a printed copy at home as Internet itself may not be available in a disaster, and to rehearse evacuation by actually visiting an evacuation site nearby that is designated by a local government. Such a site is supposed to be safer itself and you would be rescued more likely than other places.
Link: Tokyo Emergency Evacuation Information (in Japanese but with language buttons at top for machine translation)
Link: MLIT Emergency Evacuation “Portal” site (English)