Happy lass finally touring in Africa and Asia, say (10)

'africa and asia say' is the definition.
(Africa and Asia are continents)

'happy lass finally touring in' is the wordplay.
I cannot really understand how this works, but
'in' is found in the answer.
'happy' could be 'content' (associated in meaning) and 'content' is located in the leftover letters.
A single letter 's' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?