As with all things Japanese, they of course have miniature beer cans.
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105¥ for 135ml, easy to carry in your pocket for those emergencies where you just need to have a beer
I am not sure who the target audience is for these little cans; Women, children, pocket-ninjas? I estimate it would take about 36 of these to begin to get drunk… well for me. For some of you hardier folks it would probably be more like 100.