The wrapper isn't exactly tasty, to be honest with you. It's almost tasteless, not exactly the perfect way to start a piece of candy that you want to be sweet. Actually, oblaat is used to coat capsule medicines as well, which is a horrible correlation for your tongue to make.
But you get to the bontan pretty quickly. Bontan (or buntan) is a grapefruit-like citrus fruit, except it's much larger. I see them from time to time in the supermarket. The flavor isn't very citrusy, but I noticed it. I'm not a big fan of grapefruit, but the flavor here is milder and sweeter - possibly due to manufacturing, or due to the fruit itself being sweeter.
Note that this shouldn't be confused with Botan Ame, another candy that comes from Japan.