Japanese people really cares about the bubbles of beers. Almost they like to drink more bubbles than liquid of beer. Japanese beer is very bubbly and usually the ratio of bubbles and beer is 3:7. All restaurants and bars follow this rule even though such as rule does not exist. But it is hard to create bubbles when pouring the beer into the glass at home. Therefore beer companies sell beer bubble maker to households to enjoy their beer experience at home. it is unsure that Japanese people care about beer bubbles so much but according to the informant, tasty bubbles indicate the freshness of beer.