|Portrayed by||Akihiro Kitamura|
|Occupation||Former accountant at Yamagato|
Hiro receives a call on the Dial a Hero line from Tadashi. He's on top of the Yamagato building and tells Hiro that he's going to commit suicide. Hiro runs up to the rooftop and recognizes him as an account with Yamagato Industries. Tadashi explains that he was fired a month ago for inappropriate behavior after he photocopied his butt during a New Year's Eve party. Since then he's been fooling his family by pretending to go into work each day. He doesn't believe that Hiro can travel back in time and jumps to his death.
Hiro travels back in time and successfully stops the incident. When he returns to the present just before Tadashi made his call, he gets the same call again. This time, Tadashi photocopied his butt during the Emperor's Birthday celebration and was fired. He jumps to his death again. Hiro then goes back 45 more times to stop Tadashi from getting himself fired. Hiro finally sits down with Tadashi and talks. He figures Tadashi must really hate his job to deliberately get himself fired so many times, and advises him to tell his family what he really feels. He insists that life is a gift and Tadashi shouldn't throw it away. Hiro promises to be his friend no matter what and the two men shake hands before Tadashi finally leaves the roof.
- According to the casting call, Tadashi is between the ages of 25 and 45. He is described as an "office drone in Tokyo desperate to end the monotony. Humor is not lost on him."
- For other uses of Tadashi, see Tadashi (disambig).