Like January, February is a good time for visiting Japan as the weather is usually sunny and dry and sightseeing spots are not crowded. The downside of a visit in winter are the relatively short days (sunset is around 5:30pm in Tokyo) and the vegetation's barren state.
1 A healthy person drinking approximately 2 liters of water per day makes 800 to 2000 ml of urine per 24 hours (4).  If the urinary system is healthy, the bladder can hold up to 16 ounces (2 cups) of urine comfortably for 2 to 5 hours (5).
I drank my first bottle at 6 pm and the taste wasn't great but at least not the giant containers of the past! It took affect about 10 minutes after I finished drinking all of my water. I've now been in the bathroom for over 2 hours and hoping this ends at some point soon! I'm dreading the repeat at 6 am....