As Stylecaster notes, Suga goes by not just that sweet nickname but also Yoongles, Yoongs, Min Genius, and Lil Meow Meow. His actual name is Min Yoongie. Suga was originally a producer at the band's label, Big Hit Entertainment, prior to joining BTS. In fact, back then, he wasn't going by Suga or his real name either, with Cosmopolitan confirming that the fluffy haired rapper was known as Gloss in the underground music scene before hitting the big time. In a 2017 interview with Cuvism magazine (via Koreaboo), Suga confirmed that he went by Gloss in his hometown of Daegu, but Big Hit didn't really get it. 

Legendary CEO Bang Si Hyuk, who typically goes by his own nickname, Hitman Bang, suggested Suga, and the rapper agreed because he felt like it was a nice match for his onstage look. Likewise, the name Suga also nodded to the position he played in basketball, shooting guard, since the nickname is technically made up of the first parts of each of those words.

Elsewhere, Jungkook originally wanted to go by Seagull before sticking to his real name, alongside Jimin. Evidently, Suga needed something to match his sweet personality.