Hong Si-young (Korean: 홍시영; born January 24, 1991), known professionally as Giriboy (기리보이), is a South Korean underground hip-hop musician under the label Just Music. He debuted in November 2011 with single "You look so good to me (Feat. Swings)". He is also a part of Do’Main (other members include; Gganmo, Ugly Duck, 긱스, Babo, Zico and Andup).