There are 102 unique swords and spears to be found in Amana (disregarding custom weapons), and you're going to have to find most, if not all, of them to earn the Stance Mastery trophies.
Upper Stance (Images)
Kokushi-tou
Ochigumo
Sasakure
Agemaki
Ishimatsu
Todomeki
Dasaku
Shishi-Funjin
Ryurai-Zetten
Nozuchi Old Style
Samehadamaru
Ookuronama
Batsu-ichi
Monka-Bokuto
Hoe
Middle Stance (images)
Moderate Blade
Akisame
Wasabi
Utsusemi
Kikusui
Rehou-Masakuni
Onikirimaru
Samurai Sword
Dull Blade
Kakitsubata
Chabashira
Gankutsu-tou
Oborozukiyo
Manji-Kabura
Kabura-Sutegi
Bokuto
Stick
Tuna
Lower Stance images)
Amanojaku
Soumatou
Caterpillar
Gokumon
Ebiten
Hassakutou
Amabiki
Toragozen
Murasakimaru
Kofu-Zecchi
Ippatsumaru
Ouganken
Side Stance (images)
Shigemori
Shindou
Tuchigumo
Hisame
Harusaki-Kobeni
Chikotsu
Matsukaze
Secchin
Oukasagetsu
Kagebouzu
Mujin-tou
Kansei
My Hoe
Draw Stance (images)
Kunisada
Hakugei
Tamayura
Shirai-tou
Suzumushi
Yudachi
Hyakki-Yagyo
Haijin
Gekkou
Benihime
Zannkimaru
Single Stance (images)
Benibotan
Yaochou
Ama-Otome
Seimei
Oboro-Nue
Soukasuiren
Saboten
Hakuu
Nozuchi New Style
Binetsu
Biteikotsu
Short Green Onion
Ninja Stance (images)
Sayoshigure
Kizume
Kuzu-no-ha
Yume-kochou
Yagarasu
Muramasa
Kuro-tonbo
Zangetsu
Ukigumo-kodachi
Kurotaka
Spear Stance (images)
Houzuki
Masai
Sazanka
Kotobuki-Taisha
Mikazuki
Jakou
Rasetsunyo
Endou
Bamboo Spear
Long Green Onion
Broom
Character-Specific:Koukushi-tou - Shuzen, Instant Kill
Ryurai-Zetten - Shuzen
Nozuchi Old Style - Dojima (Younger)
Samehadamaru - Shuzen, Instant Kill
Ookuronama - Misae, "Misae's Challenge!" job
Batsu-ichi - Genjuro Matsuzaki
Kikusai - Shinnosuke, Instant Kill (rare)
Samurai Sword - Dona
Kakitsubata - Syuzen, Misae's "Assassinate Lord Shuzen!" job
Oborozukiyo - Shinnosuke
Bokuto - Sensei
Gokumon - Killer, Oryo's "Price With A Price" job
Tuna - Nyanya
Toragozen - Setsuen
Kofu-Zecchi - Shuzen
Ippatsumaru - Joji, "Assassinate the Assassin!" job
Chikotsu - the soldier who gives the "Fillet A Tuna" job at Amana Castle
Oukasagetsu - Vicious Outcast, Oryo's "Beauty and the Beast" job
Kansei - Kasumi
My Hoe - Shuzen, Instant Kill (rare)
Zannkimaru - Kiyonari's "The Homeless Mighty God!" job
Oboro-Nue - Itsuse, Hard (rare, has a black grip)
Hakuu - Itsuse
Nozuchi New Style - Dojima (Older)
Binetsu - Osada
Biteikotsu - Oryo, "Oryo's Interest" job
Muramasa - Otome
Kuro-tonbo - Kirie
Zangetsu - Nanba (Fujimori general, replaces Kirie in cutscenes if Kirie is killed)
Kurotaka - Zaji
Ukigumo-kodachi - Koharu (Omiki Town, onion patch) (rare, black grip and sheath)
Rasetsunyo - Yuma
Broom - Gajiro (Posting Station, sweeping the ground)
Location-Specific:Monka-Bokuto - Guard Gate, outside dojo
Hoe - Takatane Village, in a barn
Moderate Blade - sold by most vendors, default weapon
Dull Blade - Castle Minori, in the weapon storage shed
Stick - all areas, scattered on the ground
Amabiki - Castle Minori, outside of the southside building beyond a hole in the kitchen wall
Shirai-tou - The Road, in a hollow tree, use the stone ramp to get inside.
Short Green Onion - Omiki Town, onion patch
Houzuki - Kuchihagahara, in the tent
Bamboo Spear - Takatane Village, in a barn
Manji-Kabura / Kabura-Sutegi:You can trade 10 Golden Eggs to the Fabled Merchant, who sometimes at The Road, for the Manji-Kabura. Speak to him after making the trade, then travel to Takatane Village and rest until Night. You'll meet a samurai carrying the Kubura-Sutegi outside of the blacksmith's... kill him before he kills you.
Stance-based Farming Opportunities:Draw Stance - Kirizo, Omiki Town (Night), samurai with green kimono / prayer beads
Spear Stance - Yukino, Omiki Town 18:00-0:00
All Stances - Suspicious Person, randomly spawns in all areas (Night), samurai with green kimono / straw hat
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