This is a Kosen Judo competition between the former “imperial” universities in Fukuoka, Japan.
Kosen Judo has a different rule set from the standard kodokan judo rule book. Kosen judo allows for more newaza (ground fighting). Kosen judo is basically “old” judo.
The new rules to judo have become stricter and stricter. Unlike kodokan judo you can pull guard, and attack the legs for single leg takedowns, leg picks and more.
One of the guys from my new judo dojo here in Fukuoka told me about the competition and we went together. He trained kosen judo at Kobe university. Kosen judo is more like BJJ, but with the throws and is perhaps a little more simpler than modern day BJJ.
There are no leg locks in Kosen judo, but you can do ashi garame and I saw many players doing something like an ankle hold or my friend said heel hold.
The matches were 6 minutes long and the winner would stay. The coach would chose who would fight next. I think the team with the most points would be the one to win.
I didn’t learn all the rules, but there was a tie between Osaka university and Tohoku university.