Swords and Seasons — Care Wisdom from Japan's Four Seasons

Japan's four seasons significantly impact sword storage. Understanding seasonal considerations is essential for preserving fine blades.

Spring (March-May): Pollen and yellow sand season. When handling swords, ensure good ventilation to prevent fine particles from settling on the blade.

Rainy season to summer (June-August): The most critical period. Rust develops rapidly when humidity exceeds 80%. We strongly recommend using a dehumidifier. Moisture can accumulate even inside shirasaya, so perform maintenance twice monthly.

Autumn (September-November): A relatively stable period. Ideal for maintenance and storage environment checks. Replace sword oil and inspect shirasaya condition.

Winter (December-February): Watch for heating-induced dryness. Sudden temperature changes cause condensation, leading to rust. Use a humidifier to maintain 40-60% humidity.

We strongly recommend placing a thermometer and hygrometer in your sword storage area year-round.