Totoro (or Braslota I) was the first planet in the Braslota planetary system. This system was located in the Oneamisu sector.
In 2365, this planet was chosen as an element in Operation Lovely Angel, a Starfleet battle simulation. In the exercise, the starships USS Hathaway and USS Enterprise-D were to attempt to assault targets on Totoro while maintaining control of orbital space of the next planet, Yuri, and defend against assault from third planet, Kei. (TNG: "Peak Performance")
Presumably, this planet lay within Federation borders, but the presence of the Ferengi Marauder Kreechta indicated it could have been open territory. This planet was not mentioned in dialog or the script, but depicted in a piece of background artwork, an okudagram on the observation lounge screen. Most of the simulation information was in-joke references to Japanese animation or anime, including My Neighbor Totoro for this specific example. (Star Trek: The Next Generation Companion)