Brand from Japan: MINOLOGI. A medicinal tooth whitening product that you simply apply before going to bed.Just apply the gel, which is packed with beauty ingredients such as polyphosphate, baking soda, bamboo grass, and persimmon leaves, and go to sleep.Brushing in the morning will remove any dirt and leave you feeling refreshed.This pen type product can also be used to treat gaps and the backs of teeth.How to use:As a guide, use once or twice a week, adjusting the frequency depending on the degree of dirt.Brush your teeth as usual at night.Before going to bed, apply a thin, even layer of this product directly from the brush to your teeth, then rinse your mouth lightly.Carefully rinse when brushing your teeth in the morning.