Puljic is the son of a Croat and a German. He grew up in the Börnig district of Herne and lives there to this day. He attended the Börsinghauser elementary school and then the Otto-Hahn-Gymnasium in Herne. MIKI has been actively playing football since the age of three, including in the youth teams of VfL Bochum and Westfalia Herne. He currently plays for FC Herne 57. He is a fan of Borussia Dortmund and a member of the BVB fan club Los Borussos.
On the occasion of the 18th birthday of a cousin, Puljic recorded his first song in 2007. In 2011 he and the singer Diamond won the title of “Revierkönig” at the Cranger Kirmes in Herne. 
In 2011 he wrote a farewell song for Dedê, a player from Borussia Dortmund,  who then met with MIKI.  MIKI’s biggest appearance so far was when he appeared in front of around 80,000 people during the half-time break of Leonardo Dede’s farewell game on September 5, 2015 in Signal Iduna Park.
In July 2012 the Mo Leitner song was released, which he dedicated to the Dortmund player Moritz Leitner. 
In 2013 MIKI was signed to Reeces label Kopfnussmusik. With the other two rappers of the label at the time, Akkord and Reece, he released the song Hast du Jetzt what du want? In June 2013 after Mario Götze left Bayern Munich. Thereupon Götze demanded damages from the rappers.  The rappers signed a cease and desist letter. After that, Götze apparently did not pursue the claim for damages. 
The song Cuba, Cuba! from 2013,  which is dedicated to the Dortmund player Jakub Błaszczykowski, Puljic was invited to the opening of the Błaszczykowski Sports Center Kubatura, where he and Reece performed.
In December 2013 MIKI’s debut solo album Malochersohn was released by Kopfnussmusik. In the first calendar week of 2014 it rose to number 94 in the German album charts