Puyo Puyo!! 20th Anniversary
It is the second anniversary game of the series and therefore has more similarities with "Puyo Puyo! 15th Anniversary" than with "Puyo Puyo 7". This game came out 4 months before "Sonic Generations", which also celebrates the 20th anniversary of the Sonic games. There are 24 playable characters, each with their own 8-stage course (similar to Puyo Puyo! 15th Anniversary). This game, like its predecessor, was only released in Japan.
Story
It was just another day for our protagonist, Ringo Andou. Her friend Maguro Sasaki visited Ringo and Risukuma in their club room. Risukuma was conducting an experiment with a boiling flask, but it went wrong and the three of them were blown into another dimension...