Hope is Sophie’s dagger, given to her by Ro in Stellarlune. Ro forces Sophie to name the dagger, which she thinks is unnecessary, but after being put under a time limit, she names it "Hope", which Ro makes fun of. Before Sophie decided on the name, other possibilities were 'Percy' and 'Legolas', though she decided against it. The dagger's original name was Lutguardia.
Ro gave this dagger to Sophie so she could train with it. At the end of Stellarlune, Keefe takes Hope from Sophie's holster and sneaks behind Lady Gisela to stab her but fails.