Yoshimitsu's first appearance was in 1994's original Tekken. Kunimitsu's story in Tekken 2 reveals that Yoshimitsu's blade is passed down through the Manji Clan's leaders. The clan is dedicated to a mission to help the weak and fight the oppression.
About one hour after cooking. After that, any food can become tainted and needs to be refrigerated to keep the bacteria in control. If it is uncooked, it needs to remain refrigerated-but will only remain fresh in this state for about 2 or 3 days at most.
Since it is a custard base, it would be best not to allow it to sit out for more than an hour - total. From the FDA website and a Department of Health source, cooked foods can be left out for up to 4 hours after they are removed from the oven. This is a regulation for restaurants.