From their website:
The wait is almost over for the next expansion in the Monsterpocalypse CMG. Series 5 Big In Japan will rampage its way onto store shelves Friday June 18th.
Also a limited quantity of Series 5: Big In Japan Mega Packs (PIP 50031) and Big In Japan Launch Kits (PIP 50032) are still available. The Mega kit is perfect for collectors and includes a case of Big In Japan Monster Boosters, a case of Big In Japan Unit Boosters and a free limited edition Mega Mechathugrosh. The Big In Japan Launch Kit is the perfect way for stores to celebrate the release of Big In Japan in a monstrous way. Each Launch Kit contains six Big In Japan Mega Packs and two extremely limited Mega White Dajan figures for use in the Big In Japan Launch Event. These kits will only be available while supplies last so don’t miss out. Talk to you local game store and make sure they are ready for Big In Japan June 18th.