I bought one about 15 years ago while living in Japan. After moving back to US, our 10 year old egg cooker finally wore out. We bought a replacement (another brand) but the eggs blew up.After that experience, I studied through Amazon and found this one stating it was made in Japan and, at that time, shipped from Japan so ordered one. After seeing it worked nicely, same as the previous one bought in Japan, I bought eight more for Christmas gifts.Yes, being a Japanese product, made for the Japanese market, the instructions are in Japanese language. There is a set of pictures that illustrate quite nicely to add water to the mark and microwave for 10-12 minutes, but this is for a low wattage microwave 700-800 watts. My microwave is 1250 watts and takes about 6-7 minutes for hard boiled depending on how many eggs.