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TSUKISHIRO: The Ultimate Expression of MOONCASTLE dedicated to the absolute limits of material and technique.
Crafted from rare Sea Island cotton and knitted in 16-gauge, this piece features a specialized 'gassing' process that brings out a natural, silk-like luster. The result is a garment with a smooth touch and sublime comfort. Its clean, dignified silhouette reflects the true quality of premium materials.
How to Wash
While hand washing is the best way to preserve the life of your knitwear, our Ice Cotton is resilient enough for a machine wash.
- Hand Wash: Gently immerse in cold water with a fully dissolved neutral detergent.
- Machine Wash: Use a laundry net and select a "Hand Wash" or "Delicate" cycle.
- Smooth While Wet: After washing, gently smooth out any wrinkles by hand while the garment is still damp.
How to Dry & Store
- Dry Flat: To maintain the perfect silhouette, we recommend drying flat in the shade. Alternatively, hang it over a thick clothesline to avoid shoulder bumps.
- No Tumble Dry: Please avoid the dryer to prevent excessive shrinkage.
- Storage: We recommend folding your knitwear for storage to prevent stretching.
Important: A Note on Shrinkage & Fit
Due to the nature of our high-twist natural cotton, this garment will experience an initial shrinkage of approximately 1 inch after the first wash.
- The "Live" Fit: You will notice the most shrinkage immediately after washing. However, as you wear it, the knit will naturally stretch and conform to your body, returning to a comfortable fit.
- Sizing Tip: If you prefer a more relaxed or loose fit from the start, we recommend purchasing one size up.
Free Express Shipping: We provide free shipping to the USA on all orders via DHL.
Delivery Time: Most orders arrive within 5-8 business days.
No Hidden Fees: All prices include customs duties and taxes. You will not be charged any additional fees upon delivery.
Tracking: You will receive a tracking number as soon as your order is dispatched from our Osaka workshop.
Our Refund Policy
- Free US Returns: No international shipping hassles. Returns are handled at our dedicated US return center, and we cover all return shipping costs.
- 30-Day Window: Items must be returned within 30 days of delivery in their original, unwashed, and unworn condition with tags attached.
- Handling Fee: To minimize our carbon footprint and support our small-batch artisanal workshop, returns of 4 items or more from a single order will incur a $20 USD handling fee. This fee will be deducted from your final refund.
- Order Cancellations: If you wish to cancel your order after confirmation, please contact us at support@moon-castle.jp within 3 hours of placing your order. This allows our workshop to manage our shipping schedule efficiently.
- Simple Exchange Process: To get your new size or color as quickly as possible, we follow a "Return & Re-order" system. Simply return your original item for a full refund and place a new order at your convenience.
- Final Sale: Sale items are final sale and not eligible for returns or exchanges, except in cases of proven defects.
How to start a return:
- Contact us at support@moon-castle.jp with your order number.
- We will email you a pre-paid UPS/USPS shipping label immediately.
- Drop off the package at any local drop-off point. Once received at our US center, we will process your full refund
Sea Island Cotton Knit: The Ultimate Texture for Summer

(Model is 182 cm / 5'11" and wearing size L)
Experience an incredibly soft, body-hugging texture combined with an astonishingly lightweight feel. This piece is designed to luxuriously transform your experience of hot and humid summers.
Sea Island Cotton: A 0.0004% Rarity
Sea Island cotton accounts for only 0.0004% of global cotton production. Because its fibers are exceptionally long and fine, it possesses a natural, silk-like luster and a smooth texture that feels remarkably gentle on the skin.
Refined Smoothness through the Gassing Process
The gassing process removes surface fuzz to prevent pilling and create a cleaner look. This gives the fabric a subtle sheen and a smooth touch that stays comfortable against your skin all day.

Exquisite Drape and Ultimate Breathability
Knitted in a fine 16-gauge with low-fuzz yarn, this piece offers an incredibly smooth, effortless feel against the skin. Its natural breathability and elegant drape keep you cool and comfortable, making it a refined choice for summer.
Calculated Details for a Beautiful Silhouette

The slim 1x1 neck rib provides a sophisticated impression, with a perfectly measured neck opening that creates a refined look.

The sleeve ribs are created with a perfect balance—neither too tight nor too loose.
The gentle ribbing at the hem provides a clean, secure fit. It stays in place perfectly, making it an ideal layer under a jacket for both work and casual wear.
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