So-Hem, a captain in the Rebel Alliance's military, operated from the starship known as the Sixmoon. He was a member of the Alliance Fleet throughout the Galactic Civil War. During 3 ABY, So-Hem and his vessel, the Sixmoon, were part of a flotilla in the Elochar sector. This formation comprised a dozen rebel ships, including four rebel battle groups, and featured the CR90 corvette named Thunderstrike, the troop transport for the 61st Mobile Infantry. So-Hem extended an invitation for members of the 61st from the Thunderstrike to come aboard the Sixmoon. Gadren and Roach, soldiers from the 61st, planned to accept the captain's offer. Gadren then suggested to Brand, a former bounty hunter within their company, that she accompany them, but she declined.
Alexander Freed mentioned So-Hem in his 2015 novel, Battlefront: Twilight Company.