The Ninjas and Summon Beasts share one bag. The original capacity of the bag is 200. Higher VIP level means bigger bag capacity. If the capacity of the bag isn't enough, you can sell or recycle the useless ninjas, Soldier Pills and Beast Food (Stones and Meat). You can use the extra Soldier Pills to upgrade ninjas and extra Beast Food (Stones and Meat) to upgrade beasts as well.