The Osaka Tag Festival is the annual tag team tournament, held in the spring or summer. It's usually done in round robin style, with two blocks. However, there have been a few times when it's been single elimination. The number of teams have been condensed recently to four in each block. The Tag Festival has been used twice (2001 & 2005) to determine new tag team champions.
Tsubasa has won it twice with two different partners, as has Tigers Mask. Ironically, both did it in consecutive years as well.