SORA’s filling is 50% premium wool blended with 50% polyester fibre; HIMARI’s filling contains 25% wool. Wool takes up and releases moisture and springs back after compression, which is why the proportion is higher in the thicker model; the polyester keeps the loft even across the whole surface. Both models have a 100% cotton outer fabric. We publish the blend ratios, not laboratory results: these are material facts, not a measured claim about how warm or dry either model sleeps.
What the wool adds
- Warmth: a higher proportion of wool adds natural warmth, useful in cool rooms and winter.
- Breathability: wool takes up moisture and releases it again when the shikibuton is aired.
- Resilience: together with SORA’s approx. 12 cm loft, it gives fuller cushioning and a balanced medium feel.
The 2026 renewal
SORA 宙 is the 150th anniversary limited edition. Its May 2026 renewal upgraded the filling to the 50% premium wool blend and added calm gray piping around all four edges; every SORA dispatched from May 2026 onward is the renewed edition.
Caring for a wool-blend shikibuton
Wool responds well to regular airing in dry weather and should not be left damp. Do not wash the whole shikibuton; protect it with a washable cover and spot-clean when needed.
Is it right for you?
Choose SORA for a fuller, warmer surface. If you prefer a firmer, steadier feel, HIMARI 日葵 with 25% wool and an approx. 8 cm firm support core may suit you better. Both models contain wool in the filling, which is worth noting if you are sensitive to it.