Tsubugai is a Japanese shellfish, a whelk, a kind of small conch-like shellfish. A toothpick or small implement is used to twist the meat out from its shell. It is not fishy, it is meaty and is extremely tasty and it also has a terrific consistency said to be somewhere between clams and poultry. Tsubugai is also a Japanese term for dishes prepared from shell fish. Tsubugai in Japanese means "shellfish".Tsubugai is a kind of small conch-like shellfish.