According to Japan Today, former world titlist Osamu Sato has decided to retire from boxing.  In Sato's first world title bout, he drew with Willie Jorrin in a WBC 122-pound title bout in February 2002.  Three months later, he won the WBA belt at the same weight with an eight-round stoppage of Yoddamrong Sithyodthong.  Another three months later and Sato was an ex-champ by virtue of a decision loss to Salim Medjkoune.  In 2004, Sato moved up to featherweight but lost to Chris John.  He retires ranked #12 by Boxingtalk with a record of 27-3-3. -- Scott Shaffer