also: きりはこ
noun
paulownia wood box; paulownia box
A box made of paulownia wood, often used for storing valuable items like tea ceremony utensils, art objects, or documents because the wood is lightweight, moisture-resistant, and insect-repellent.
祖母は大切な着物を桐箱にしまっている。
My grandmother keeps her precious kimono in a paulownia box.
この茶碗は桐箱に入れて保管してください。
Please store this tea bowl in a paulownia box.