Title: Pokémon Tretta set 5 - Search for That Trio Alongside Nyarth...
The fifth Pokémon Tretta expansion has been announced, both on the official Pokémon Tretta site and in the newest issue of Corocoro Comic. The set is titled Search for That Trio Alongside Nyarth! (ニャースとさがせ! あの3体!!), and Tretta systems will be updated to feature this set in late April.
The set will feature the Pokémon Tretta debut of "that trio", Jalorda, Enbuoh and Daikenki, as well Nyarth, who has currently only been featured on a Rookie Tretta included in the fourth Pokémon Tretta Fan Book, released March 8th. The only other Pokémon known to be featured in the set are Leafia and Glacia.
The set will debut a new gameplay feature called "Search", though it's currently unknown what it does. Both current promotional material and the title of the set indicate that it could be exclusive to Nyarth.
The six currently revealed Tretta from the set have been added to our
Pokémon Tretta section, which will be updated with new information once known.
Sources:
http://www.pokemontretta.com/tretta/t05/ and Corocoro Comic April/2013