Shobu Zukuri is Japanese and translates to "Iris (leaf) construction".
The tip of the katana resembles the thin and slender shape of the iris leaf.
This blade design became popular during the Nanbokucho era (1336 ~1392 AD) and
its popularity continued into the Muromachi period. The most remarkable point here is that the Shobu katana has the shinogi (ridge
on the sides of the blade) running the entire length of the sword, and has no
yokote or kissaki. Where the ridge on a shinogi zukuri blade for example does
stop at the yokote line.
There are 2 styles of Shobu katana, the first style has the ridgline running
into the kissaski of the blade. The second , and in these days more seen, style
has a ridge that is stopping a few millimeters before the kissaski.
This katana is has the latter mentioned shape.
The absence of the yokote and the flow of the ridgline into (or just before)
the kissaski forms a long and graceful cutting point. It’s generally so
sharp it can be used as a cutting point rather than a piercing one. This allows
the sword to be used more like a scalpel than a slashing weapon.
Another (less known) characteristic is the fact that the gi (area on the blade
above the ridgeline) angles sharply to the mune (spine/ back of the blade).
This is typically much narrower than on a comparable shinogi-zukuri blade for
example.
