Manga creator duo Yudetamago announced at the end of their 313th Kinnikuman manga chapter on Monday that the manga will start a hiatus of about one month on April 20, due to the current effects of the new coronavirus disease (COVID-19) and the resulting April 7 state of emergency declaration. Yudetamago explained that the duo and their assistants commute to a studio where they produce the manga manually, using pen on paper, for long hours over several days every week. In addition, many staff members live with elderly family members.
After consulting with Shueisha, Yudetamago decided to put the manga on hiatus for now. They plan to resume the manga on Monday, May 18, but the COVID-19 situation has been changing from day to day. If those plans change, they will notify their readers. In the meantime, Shueisha will post previous one-shot manga and other works by the duo for free. The duo exhorted fans to "knock out the virus with our friendship power!"
The creator duo Yudetamago resumed their original Kinnikuman wrestling manga as a free web manga in 2011. The creators went back to their first 1979 Kinnikuman storyline and continued where they last left the story in 1987. The original manga has inspired various television anime series and films. Yudetamgao previously published a Kinnikuman one-shot manga in Shueisha's Grand Jump magazine in 2015, and then published a one-shot in Weekly Shonen Jump for the first time in 11 years in June 2019.
Toy figures of Kinnikuman were imported into the United States under the "M.U.S.C.L.E" brand name in the 1980s. Viz Media then released Takashi Shimada and Yoshinori Nakai's Kinnikuman Nisei - Second Generations manga sequel in North America as Ultimate Muscle: The Kinnikuman Legacy, and 4Kids broadcast the anime adaptation on television.
Shueisha announced on April 8 that the Weekly Shonen Jump magazine, the original home of the Kinnikuman manga, is delaying the contents of this year's 21st issue by one week to April 27, due to a possible COVID-19 infection in the editorial department. Shueisha announced a day later that it is delaying Demon Slayer: Kimetsu no Yaiba volume 20 and 30 other new manga volumes from May to May 13 due to COVID-19 countermeasures.
Source: Shueisha (link 2)