Ken'ichi Kitazawa's Môningu Musume. tokuban: 13-nin-gakari no Kurisumasu is a TV special that was originally broadcast on Fuji TV in Japan on December 22, 2001. Below are links to a two-part English-subtitled version of the entire "13-nin-gakari no za gaman" segment of that special, as well as one to an English-subtitled clip from that segment. (Three years ago, I had a collection of numerous vidcaps from that segment; unfortunately, I apparently never saved it on disc, although for some reason I did save a vidcap of the title of that special!) A clip from that segment has been played a couple of times on The Colbert Report.
Hajime Yarigasaki's The gaman II is an AV that was released on DVD (SDDM-723) in Japan on November 4th of last year by Soft On Demand K.K. (Sofuto On Demando K.K.). There's a link to a downloadable trailer for it on the thread "The Japanese are just weird" in The Bin forum of The Rue Mortuary - the Rue Morgue message board. (There are also links to downloadable trailers for Ganja Yoshino's Petit Exposure (Puchi rashutsu) and Armen Oganezov's Everything is Allowed.) With regard to that trailer, viewer discretion is strongly advised.
Google Video: "13-nin-gakari no za gaman" clip (English subtitled; 1 min. 28 sec.)
Google Video: "13-nin-gakari no za gaman" segment - part 1 (English subtitled; from 27:23 - 30:11)
Google Video: "13-nin-gakari no za gaman" segment - part 2 (English subtitled; from 00:00 - 11:13)
Internet Movie Database: Môningu Musume. tokuban: 13-nin-gakari no Kurisumasu
The Rue Mortuary: The Bin: "The Japanese are just weird"