In Japan, just like on the continent, they love their beer with a healthy head of foam. Which explains why gadgets like the self-frothing beer mug, and now this ultrasonic frother even exist.
Takara Tomy's £26 Sonic Hour works a lot like the self-frothing beer mug, using vibrations to kick up the bubbles and produce a thick head of foam on your lager. But instead of requiring you to then drink it from some novelty stein, it works with any glass you place on its platform. It's like having your own terrible bartender, minus the boring chit-chat.