On April 20, Choo Sung Hoon wrote on Instagram, "You worked hard during your military service~ Jaejoong is handsome as always ^^." and shared a photo snapped with the two stars, as well as other acquaintances.
Previously, Choo Sung Hoon made a cameo appearance in 2014 drama 'Triangle', which starred Jaejoong and Siwan. Since then, the three have continuously shown their close friendship.
Meanwhile, Siwan was recently discharged from his mandatory military service on March 27.