Though we can’t confirm this, it seems likely that in putting together their for-adult-men Pokémon lucky bag, Shimamura drew from left-over items they’d stocked up on for last Halloween.
The bag itself is part of the bundle, as it’s a cloth tote bag graced by Mimikyu.
Though officially listed by Shimamura as a fukubukuro/lucky bag, which usually denotes a mysterious blind-buy package, they actually let shoppers know exactly what was in the for-adult-men Pokémon fukubukuro prior to purchase.
The result is that there are a lot of fans who got into the series as kids and continue to enjoy it as adults.