Tokubetsu, which simply means "special," is an odd category. In Japan, it's legally defined as being made from sake-specific rice (such as Yamada Nishiki), polished to 60% or less (ginjo equivalent), or brewed using a "special" method.
99% Of the time, tokubetsu sake is so categorized because of the first two reasons, sake-specific rice or polishing. So why not use other terms, like junmai or ginjo? Usually it's because the brewery already has a junmai and ginjo in their product lineup: one which loyal customers have enjoyed for years. Or maybe it's polished to 60%, and it's delicious enough to share, but it doesn't really taste like a ginjo... you don't want to disappoint your customer base by misleading them.
Tokubetsu sake is full of gems. It really feels like a space for brewery creativity and experimentation.
