When you have tea with a higher level of natural caffeine, you will feel rejuvenated.
Sencha, Gyokuro, and Matcha all contain more caffeine.
The hotter the water you use to brew, the more caffeine is released.
To help you wake in the morning or to refresh at work, brew stronger tea (using more tea leaves) and use hotter water than the recommended temperature.
For those wanted less caffeine, babies, pregnant women, or before bed, use tea with less caffeine.
It is recommended to give the second brew of tea or diluted Hojicha or Bancha which contains the least amount of caffeine of green teas.