Seems that someone working for Shueisha got infected with corona.
https://www.shueisha.co.jp/info/20200407.pdf
"On April 6, our employee (in their 40s, editor) was confirmed to be infected with the new coronavirus.
The employee had a fever on March 26, consulted a medical institution, and was refraining from coming to work.
On April 3, he underwent a PCR test and was diagnosed positive on the night of the 6th.
In response to this, we are taking the following measures while cooperating with administrative organizations.
-Temporary closure and disinfection of the floor where the infected person had worked on
・ Checking the work history of the infected and identifying close contacts
・ Thorough observation and reporting of health of close contacts
We have been working from home on a company-wide basis since 6th, with a continued need to prioritize the safety of stakeholders and prevent further transmission.
We will take appropriate measures.
Thank you for your understanding."