@FKM:
So there is this image, i guess it says something important
http://tonarinoyj.jp/info/onepunchman_shibuya/images/main.jpg
says that a huge OPM poster called "HEROES" will be put up right in front of the Shibuya station ticket gate in Tokyo from May 1st(Wednesday) to May 14th (Tuesday) and it's asking all the fans to come and see it, It also mentions that the first three volumes of OPM have sold more than 700.000 copies.
The big text on the right says:
"READERS, THIS IS SAITAMA."
The big text on the left:
"IT'S HIS DEBUT IN THE MOST MAJOR TOWN IN JAPAN, SHIBUYA!"
Thanks to TranslatorFag for this.