Katana Amber Sakura Kobuse Blade Kōhaku Zakura Koshirae 琥櫻

Clay Tempered Full Tang Shinken (真剣) | Amber Sakura Katana: TangGu (湯谷) Kobuse Blade (甲伏造) + TangGu (湯谷) Kōhaku Zakura Koshirae (琥珀桜拵)

The blade is forged in Kobuse-zukuri（甲伏造） construction, where a hardened outer layer encases a softer core to achieve both durability and cutting performance. The surface displays a refined combination of Masame-hada and Mokume-hada（柾目肌交杢目肌）, with straight grain lines interwoven with flowing woodgrain patterns created through orikaeshi-tanren（折返し鍛錬） folding. Along the edge runs a gentle notare hamon（湾刃文）, its smooth, undulating waves formed by meticulous clay tempering（覆土焼入れ）. The fittings follow a cohesive sakura theme with an elegant, traditional aesthetic. The mokko-style tsuba（木瓜鍔）, forged from white copper and finished in a blackened patina, features a raised sakura motif, giving the guard a dignified sense of ornamentation. The fuchi-kashira（縁頭）, also crafted from blackened white copper, carry matching raised sakura carvings that unify the theme. Beneath the wrap rests a pair of blackened white-copper menuki（目貫） in a floral design. The habaki（鎺） is made from white copper with a clean, smooth finish. The tsuka（柄） is wrapped in brown leather style tsuka-ito, tightly applied over hishigami to maintain crisp, symmetrical diamonds, while the underlying black samegawa（鮫皮） provides strong contrast and refined texture. The saya（鞘）, shaped in the uchigatana style, is reinforced with water buffalo horn（牛角） at the koiguchi（鞘口）, kurigata（栗形）, and kojiri（鐺）. Its exterior is finished in Orange Nashiji lacquer（橙梨子地塗）, presenting a warm, shimmering surface reminiscent of fine pear-skin particles under shifting light. 

TangGu (湯谷) Kobuse Blade

This blade is hand-forged (Tezukuri / 手作り) using our own refined steel, following the principles of Japanese swordsmithing. It features a Kobuse-zukuri (甲伏造) laminated construction, reflecting the structure of traditional Tamahagane (玉钢) swords.

Blade Forging Details

• Blade Name: TangGu Traditionally Forged Kobuse Blade (甲伏造)
  

• Forging Method: This blade is forged in the Kobuse-zukuri（甲伏造） style, where a hardened outer layer of steel is forge-welded over a softer inner core. It is differentially hardened using traditional clay tempering（覆土焼入れ）, resulting in a sharp edge, resilient spine, and a visible hamon（刃文） that reflects both performance and craftsmanship.

• Materials: Steel refined in-house using traditional methods（伝統的手法による自家製鋼材）.

• Purpose: Suitable for Kenjutsu and Tameshigiri (test cutting) practice, collection, and display. Unsharpened blades are available for Iaido upon request.

Blade Specifications

• Blade Length (Nagasa刃長): Approx 71 cm
• Tang Length (Nakago 茎長): Approx. 24 cm
• Width at Base (Motohaba 元幅): Approx. 32 mm
• Thickness at Base (Motokasane 元重): Approx. 6 mm
• Width at Tip (Sakihaba 先幅): Approx. 24 mm
• Thickness at Tip (Sakikasane先重): Approx. 4 mm
• Kissaki Length (Tip 切先長): Approx. 35 mm
• Mekugi-ana (Peg Hole 目釘穴): 1

Blade Characteristics

• Shape: Shinogi-zukuri (ridged blade 鎬造), Iori-mune (flat ridged spine 庵棟), Chū-kissaki (Medium-sized tip 中切先)

• Forging Pattern (Hada 鍛肌): The forging pattern shows Masame-hada with Mokume influence（柾目肌交杢目肌）, where masame-hada（柾目肌） fine straight grain lines run longitudinally along the blade, and mokume-hada（杢目肌） swirling woodgrain-like patterns appear in layers. This is achieved through folding and directional forging in the orikaeshi-tanren（折返し鍛錬） process.
• Temper Line (Hamon 刃文): The blade features a notare-style temper line（湾刃文 / Notare Hamon）, its gentle, undulating waves formed through traditional clay tempering（覆土焼入れ / Fukutsuchi Yakiire）. 

Special Features and Workmanship

Hi (Groove) Engraving

• Type: Hi-Nashi (樋なし)
• Processing Range: None (No bohi) – Solid blade for added weight and strength

Polishing Work

• TangGu Polishing Levels:
  • Highest-grade shaping polish 最上・成形研磨 
  • Superior rough polish 最上・下研ぎ 
  • Detailed final polish 最上・仕上げ研ぎ 

Fittings and Mountings

Blade Fittings

• Tsuba (Handguard 鍔): A mokko-shaped tsuba (木瓜鍔) forged in white copper and finished in a blackened patina, featuring an elegant raised sakura motif. 
• Fuchi-Kashira (縁頭): Made from white copper with a blackened finish, both pieces display raised sakura carvings.
• Menuki (目貫): A matched pair of blackened white-copper floral menuki.
• Habaki (鎺): A smooth-finished white-copper habaki.
• Handle Wrapping ( 柄巻): Wrapped in brown leather style tsuka-ito, tightly applied over hishigami to maintain crisp, symmetrical diamonds and a firm, secure grip. Genuine leather wrapping is also available upon request.

Saya and Accessories

• Saya (Scabbard 鞘): The saya is made in uchigatana koshirae style（打刀拵）with buffalo horn fittings（牛角 / Gyu-kaku）at the koiguchi（口金）, kurigata（栗形）, and kojiri（鞘尻）.
• Saya Lacquer (鞘塗): Finished in Orange Nashiji lacquer（橙梨子地塗）
• Sageo (Cord 下緒): Japanese-made sageo available in multiple colors

Measurements

• Blade Weight: Approx. 0.6 kg
• Sword Weight (without Saya): Approx. 0.95 kg
• Total Weight: Approx. 1.2 kg
• Overall Length: Approx. 102 mm