Osumamu attended Kotobabi Technical Institute High School in Accra, and earned a four-year college diploma in mechanical engineering.

Osumanu Adama compiled an amateur boxing record of 54–4 with twenty knockouts in Ghana as a light middleweight.

[5][6] Adama turned professional in 2001, with a second-round knockout of Akeem Alarape in the Kaneshie Sports Complex in Accra, racking up seventeen wins in Ghana between 2001 and 2010.

[7][8] His first two bouts in the United States in August 2009 and April 2010 were fought without proper training time at super middleweight and light heavyweight, and Adama lost two close decisions.

[1][2][3][12] After not fighting for over a year, Adama won a split decision over ten rounds over Grady Brewer in March 2013, and was ranked 16th in the world by BoxRec.

[13] Adama then (22–3, 16 KO) earned a bout against Gennady Golovkin for the WBA and IBO middleweight titles.