| 81diver | |
 First tankōbon volume cover, featuring Soyo Nakashizu | |
| ハチワンダイバー (Hachi Wan Daibā) | |
|---|---|
| Manga | |
| Written by | Yokusaru Shibata |
| Published by | Shueisha |
| Imprint | Young Jump Comics |
| Magazine | Weekly Young Jump |
| Demographic | Seinen |
| Original run | September 7, 2006 – July 17, 2014 |
| Volumes | 35 |
| Television drama | |
| Directed by |
|
| Produced by | Yasuyuki Azuma |
| Written by | Kazunao Furuya |
| Music by | Hiroyuki Sawano |
| Original network | Fuji TV |
| Original run | May 3, 2008 – July 19, 2008 |
| Episodes | 11 |
81diver (Japanese: ハチワンダイバー, Hepburn: Hachi Wan Daibā) is a Japanese shogi-themed manga series written and illustrated by Yokusaru Shibata. It was serialized in Shueisha's seinen manga magazine Weekly Young Jump from September 2006 to July 2014, with its chapters collected in 35 tankōbon volumes. The story follows Kentarō Sugata, a shogi player who, after failing to go pro, is inspired to take the game seriously again following a defeat by Soyo Nakashizu, a champion with a surprising side job.
An 11-episode television drama adaptation was broadcast on Fuji TV from May to July 2008. It starred Junpei Mizobata as Kentarō Sugata and Riisa Naka as Soyo Nakashizu. The title refers to the main character's shogi nickname, which comes from the words of his former teacher who once told him to dive into the 9 by 9 (81) squares of the shogi board.