on rainy days umbrella bags are placed at shop sbrabs. it's considered impolite to carry an umbrella that might get others wet. ordinary umbrellas have a water repellent coating. but the coating wears off over time. this umbrella was created with etiquette in mind. one shake is all it takes to shed every drop. this stay dry umbrella was developed by a small company with only 15 employees. unlike ordinary umbrellas the material used in a stay dry type actually sheds water. lotus leaves provide a clue. water droplets that fall on the leaves turn into balls and roll off. it's possible to see in a microscopic level. there's a texture on the leaf surface that repels water. but developing a similar texture wasn't easy. they first wove a material that was textured like let test tus leaves. it repelled water droplets, but final particles leaked through the gaps. plugging the gaps caused droplets to stick to the surface like on a plate of glass. water proofing and water repellant were incompatible ideas. >> translator: our tests failed again and a