For those planning to return to your home country for the summer vacation. As of July 7th, you will be able to re-enter Japan if you have a valid status of residence.
When re-entering Japan, everyone, regardless of nationality, needs to undergo the following procedures described on the following site.

Japan's Border Control Measures
https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/0000121431_00209.html (Scroll down for English)

On re-entry you are required to isolate yourself at your accommodation (registered location of isolation) or home, and NOT come into physical contact with anyone.
You are required to report your location and health condition daily as pledged. You will not be allowed to use public transportation, nor from the port of arrival, so plan properly before leaving. The university will not provide financial support.

Regulations on Mandatory 14-Day Isolation upon entry
https://www.hco.mhlw.go.jp/
https://www.hco.mhlw.go.jp/en/　(English)
https://www.hco.mhlw.go.jp/zh-cn/ (Chinese）

Before you leave Japan, you are advised to read through, fully understand and prepare for the procedures required for re-entry.

*Note: The university will provide support (up to 50,000yen) towards expenses incurred, transportation etc., for those who meets all the requirements.
・International students registered in the academic year of 2020.
・International students who have left Japan before August 31st, 2020 and are unable to return.