Manny Pacquiao will follow former foe Floyd Mayweather and appear under the banner of Japan's Rizin Fighting Federation, the organization's president Nobuyuki Sakakibara said Monday.Sakakibara uploaded a pair of posts to Twitter -- one each in English and Japanese -- to announce the World Boxing Association welterweight champion's participation in the upcoming Rizin promotion in Yokohama on April 21.I’m here in the Philippines. RIZIN.15 will have this man involved in a way. We will be ready to announce as I get back to Japan! #rizin15 #MannyPacquiao pic.twitter.com/58lv5xwPMb"I'm here in t…READ FULL ARTICLE