With the upgrade of the assorted remaining Yui-class Scouts into Yui 7-class Scouts, the Zesuaium along the flatter front edge of the craft was harvested early on to make blast shutters for the Yui 7 Scouts as well as for other Star Army craft. The bladed part of the Yui 7, designed impractically for ramming, also had to be replaced. Unfortunately, there was little call on what to use the sharp strips of Zesuaium for.
Given the long history of the Yui-class Scout, it was decided to craft the blue metal into ceremonial (yet still fully functional) katana. These blades are then given to notable members of the ship's previous crews who had served honorably, to promising members of the new crew to attach them to the ship's long tradition, and to others who played some important role in the ship's history.
Each blade comes in the Yui-class Scout's original dark blue paint, save for the glistening unpainted monomolecular edge and etching. The name (both GSS and YSS if applicable) and known registries of the ship from which the blade was forged is etched into the Zesuaium, along with the number of the blade crafted from that specific ship. The pourous hull coating which allows the paint to adhere is still present, and is very hard to duplicate. The handle is Yamataium, so it can resist the wear of the Zesuaium blade's core by steadily regenerating, or be repaired in the unlikely event it cracks or breaks. This handle is then carefully wrapped. While the handle can be held comfortably by four and five fingered hands, the blades are quite heavy and require strength to wield effectively. They come with a Yamataium sheath with a thin layer of Zesuaium coating on the inside.
The extreme difficulty in forging the hull coating and paint, combined with the fact that every single blade is unique, can make them quite collectible militaria. Even the curvature of the blades can vary slightly, depending on from which part of the ship's edge it was taken. Lower numbered swords are typically given to veteran captains and crew for specific accomplishments, who can be looked up by the sword's registry and number. A low numbered sword from a well known ship can be very valuable, even more so if the person who was awarded the blade was famous. These kinds of blades do not come on the market very often, as they are guarded and treated with respect.
Very high numbers from ships not very well known aren't as valuable as veterans' swords naturally, but are still a tie to the Army's history, and are typically guarded with pride. It is not uncommon for a soldier or officer who owns one of these swords to wear it with their dress uniform. Some actually choose to use their blades in combat, for a yet closer tie to their ship.
These swords are manufactured under a special contract for the Star Army by the Tamahagane Company. The company delivers them to the Star Army which then handles the sale and distribution.