Why does nobody know who Tsugumi Ohba is?

Everything official about Tsugumi Ohba fits in a short paragraph, and this page will not pad it with guesses. Ohba is the pen name of the writer of Death Note, Bakuman, and Platinum End. The documented facts are these: born in Tokyo; a self described clean freak who cleans once a day; a collector of teacups and art lithographs; a film lover who reads little; and, in the most quoted detail, a writer who develops plots while holding their knees on a chair, which readers of Death Note will recognize as L's own thinking posture. No verified photograph, legal name, or biography beyond this has ever been published.

The anonymity was structural, not a stunt. Ohba and illustrator Takeshi Obata rarely met in person during Death Note's run; they first met at an editorial party in January 2004, communicated through their editor, and did not discuss even the final chapters with each other directly. The most famous writer in the magazine was, to his own artist, essentially a voice arriving by fax. Even Ohba's gender was unknown to the public for years, a gap the record only closed incidentally.

One theory dominates the speculation, and it is labeled here as exactly that. It is widely speculated, never confirmed, that Ohba is veteran gag artist Hiroshi Gamo, creator of Tottemo! Luckyman; the theory was notably promoted by commentator Toshio Okada, and its supporters cite parallels including Bakuman's plot about a one hit wonder gag artist uncle and resemblances in Ohba's storyboard style. Shueisha and the principals have never confirmed it, denied it in any definitive way, or offered another name. The honest answer to this page's question is that nobody knows because the arrangement was designed so that nobody would: the work has a name, and the person kept theirs.