An employee of Mason Lang, Takashi is well on his way to becoming invisible following his invention of the time machine. His theories seem to revolve around all times being one due to recurring patterns, such as the cloud formation in a photo of Robin's and the origami structure that both Takashi and his grandfather (Takashi's grandfather was a casualty of the atomic bombs dropped on Japan at the end of World War II, an event which resonates throughout the Invisibles as it is responsible for the "magic mirror" god form appearing in our universe) make.
Takashi lost an eye in an attack by the Agents of Karma, who are affiliated with the Japanese cult, AUM. According to Robin, his eye will be replaced in the future. In 2012, he has become a full-fledged member of the cell with Ragged Robin, Jack Frost and Lord Fanny, but will be attacked by the King-of-all-Tears just as he sends Robin to our time. What becomes of him (or anyone, for that matter) after that is a matter of conjecture at this point.