Since 1994, Downtown has hosted
Hey! Hey! Hey! Music Champ, a music variety show. It's one of four shows Downtown is currently hosting.
Heyx3 episodes typically have a Japanese music star (but sometimes a foreigner) performing a recently released single, being interviewed, and often participating in some outlandish game. They games tend to be what gets uploaded and subbed.
One group that makes frequent appearances on this show and other variety shows (which seems to be a popular format in Japan) is Morning Musume. Morning Musume is an all female vocal and dancing group which has set sales records since forming in 1997. Their membership changes over time with older girls 'graduating' and new members winning auditions.
Here are some links to Morning Musume appearing on Heyx3.
The first set of links seems to be the third competition they participated in. But, it's probably the best to view first since Matsumoto owns the show completely in the second and third parts of the competition (2nd-4th links).
2002 Morning Musume Games: Team Matsumoto vs. Team Hamada, Part 1 (selecting teams, goldfish catching)
Part 2 (shaved ice eating)
Part 3 (shaved ice eating concludes, What are my feet touching?)
Part 4 (conclusion of feet touching)
The follwoing link has the 13 members of Morning Musume as one team against Downtown and other Japanese celebrities.
The competition consists of:
(1a) Ball tossing- eveybody throwing small balls into a basket-ball style net
(1b) Ball tossing- the game is changed so that one team randomly(?) has to toss high grade chesnuts (which have sharp spines)
Live performance of Morning Musme's new single 'Mr. Moonlight'
(2) Obstacle Course
(3) Strike-Cover-Jenken (rock-paper-scissors with a twist)
(4) Relay Race
This competition has a scene which went viral years ago.
Hamada Playing Strike-Cover-Jenken
2001 Morning Musume Games (52:56 Veoh link)
The third set appears to be the first competition. Unfortunatley, it's unsubbed and incomplete. However, all of this stuff is enjoyable without subs if you enjoyed the earlier links.
2000 Morning Musume Games, Part 1 of 7 (Introductions, 1st volleyball set)
Part 3 (3rd volley ball set begins)
Part 4 (3rd volleyball set concludes, tug-of-war complete)
Part 5 (Strike-Cover-Jenken begins)
Part 6 (Strike-Cover-Jenken concludes, Shooting Galery complete)
Parts 2 and 7 simply couldn't be found. I gathered that Part 7 was a relay race like in the 2001 games and that Downtown won.
These competitions aren't taken seriously, though both sides try to win. Downtown simply wants an entertaining show. The guests are there primarly to promote their product and themselves. As a result, there seems to be a tradition that the final competition gives whichever side is trailing a chance to make a comeback. In one extreme example on a different show, one team was beating the other 2-0. To give the trailing team a chance to win, the final round was decided to be worth 2,000,000,000,000 points.