The ‘collar’, also called the neck, is the bone at the back of the head. In Japanese, the tuna neck is called ‘kama’ and can reach a weight of 5 kg. If a tuna is to be fillated, it is advisable to remove the neck first. The neckpiece contains a small piece of tasty lean red meat, also called ‘secret’ and can be found under the sievin. The lower marbled part also has a piece of toro. It is better known as ‘kamatoro’. This very extremely marbled piece of toro is small, but very tasteful.