Some possible reasons:
The manga each is based on are run in the same magazine.
The anime are aired on the same TV channel in Japan on the same day.
The anime are made by the same company.
anime info: http://www.mahou.org/Showtime/?o=ET
manga info: http://en.wikipedia.org/wiki/Weekly_Shounen_Jump#Series
For celebrating the start of Toriko anime, a Special Collaboration with One Piece was made. A 1 hour special serving as Episode 1 of Toriko and Episode 492 for One Piece.
Year later at the 1st anniversary of Toriko and because of the success of the first collaboration, a second Toriko x One Piece Collaboration Special was announced. A 1 hour special serving ...
Pair is the pair of testicles of a Ballboon.
Monkey King Bambina's Pair is the hardest to get, and also the most delicious because it is fresh off the monkey. The Ballboons hang their Pairs from the Birth Cry Tree as a mating ritual.
Retrieving Pair from the Birth Cry Tree can be accomplished with 2 means: Eating someone of similar power to yourself, or ...