On August 27, X1's large-scale debut showcase took place at Gocheok Sky Dome, Seoul where just over 20,000 people could be accommodated.
Along with the photos, Han Seon Hwa wrote, "Congratulations to my little brother!"
The photos were of Han Seon Hwa and Han Seung Woo smiling and posing with their arms linked.
The photo showed Han Seon Hwa right in the middle of the photo surrounded by X1 members in their waiting room.
In the caption, Han Seon Hwa wrote, "Congratulations to these guys as well. Big thanks to Seung Woo for giving me this great photo opportunity!"
She especially screamed with joy when Han Seung Woo appeared on screen, which clearly showed how happy she was about her brother making his debut as the leader of X1.
Han Seon Hwa was born in 1990 and Han Seung Woo in 1994, making them four years apart.
Despite their age gap, they are known to be quite close to one another.
(Credit= 'shh_daily' Instagram, 'x1official101' Twitter)
(Lee Narin, SBS Star)