Tags are used in the Yo-kai Watch Busters mode to access the different difficulty levels. The highest level, Golden Adventure, awards exclusive and rare prizes that require much less Oni Orbs to crank than the Silver Adventure's. The only issue: At a hefty price of 1000 BP, Gold Tags are difficult to buy. Instead of grinding BP to buy them, there is a much simpler and faster solution. This process can be repeated an infinite number of times with no penalty to generate a high number of Gold Tags. The steps to obtaining one are listed below:
When performing this process, choose to "Brush your teeth" as well. Doing so around 10 times will trigger a fight with Count Cavity, but the exact amount is random. He will give a Holy Exporb when defeated. While this is not an efficient way to grind Experience, it is a nice bonus when when grinding for Gold Tags. Sleeping until night instead of day will cause Mom to interrupt and offer dinner. This slows down each day's cycle by a few seconds, so always choose to sleep until morning.