The Ministry of Agriculture, Forestry and Fisheries (MAFF) has requested that we disseminate information and raise awareness about animal and plant quarantine measures.
To prevent the introduction of virulent livestock infectious diseases, the Animal Quarantine Station has strengthened border quarantine inspections on meat products and other items subject to animal quarantine. These inspections primarily focus on the carry-on belongings of international passengers and international mail.
For more details, please refer to the explanations, videos, leaflets, etc. on the following website:

Leaflet (Japanese only):
https://www.maff.go.jp/aqs/topix/pdf/this-is-a-message-to-you-ezJP.pdf

Animal Quarantine Service website (multilingual):
https://www.maff.go.jp/aqs/languages/info.html