Mai Kondo was a 52nd century alien environmental science student. The Tenth Doctor met her on Winter Wonderland, where she accidentally surfed into the TARDIS. She was on the planet for her thesis. The Doctor took her to 1814 to see the beginning of the Industrial Revolution. To save the Earth from a Hyban looking for energy, they brought it back to Winter Wonderland, where its natural cooling abilities could counteract the rising temperatures due to the planet's orbital decay. (PROSE: The Frozen)
Multi-adventures reference the rare instance when a companion is shown or stated to have multiple adventures with the Doctor but only appears in a single story.
If a medium is not mentioned, then this incarnation did not have companions who were original to that medium; it does not mean that this Doctor failed to appear in that medium.
