http://gnu.univ.gda.pl/~huckster/ff11/shinai.jpg
http://gnu.univ.gda.pl/~huckster/ff11/shinai2.jpg
http://gnu.univ.gda.pl/~huckster/ff11/shinai3.jpg
From Feast OF Swords quest
1. talk to moogle in the city - get katana
2. talk to nomad moogle outside the city
3. find armor and start killing it
4. when it dies - trade Wooden Katana to ???
5. you get Lotus Katana
6. start killing another armor
7. when it dies trade Lotus Katana to ???
8. you get Shinai.
Its kinda useless since you can't trade it to Luto Mewrilah so that your NPC would use it....