Japan's next High Class Pack will be called MEGA x MEGA Parade and release on 19 February 2027, PokeBeach reports. Pokémon has not announced the set officially. High Class Packs are Japan's premium boosters, with more cards per pack and a guaranteed special card; the previous one was Mega Dream ex.
According to the report, a pack costs 550 yen and holds ten cards. A month later, on 19 March 2027, a Mega Attack Special Set for 3,960 yen is expected to follow, PokeZentrum writes – that date is expected rather than confirmed too, and its contents are unknown.
That a product by this name is coming is likely, though: Nintendo, Creatures and Game Freak have registered the trademark "MEGA x MEGA Parade" for games and toys, as PokeGuardian reported in July. No English version has been announced.