Wikipedia describes finished tempura as pale whitish, thin, fluffy, yet crunchy. That texture is the signature of Japanese tempura: a delicate batter surrounding seafood or vegetables while remaining light rather than breadlike.
The batter is typically made from flour, egg, and very cold water. It is mixed only briefly, often with chopsticks, so lumps remain and gluten development is limited. Cold batter and minimal mixing help produce the airy, crisp coating associated with properly fried tempura. The food is cooked quickly in hot oil, which sets the exterior before the batter becomes heavy or doughy.
Crunchy does not mean breadcrumb-crusted. Tempura traditionally uses batter alone; panko-coated fried foods such as tonkatsu and ebi furai belong to a different category. Tempura is also commonly served with a dipping sauce and grated daikon, which add moisture and contrast without changing the freshly fried coating’s characteristic crunch.