Japanese hottie lived with a Guys and Dolls fan (6)
I believe the answer is:
wasabi
'japanese hottie' is the definition.
(hot Japanese plant)
'lived with a guys and dolls fan' is the wordplay.
'lived' becomes 'was' ('be' can be a synonym of 'live').
'with' is a charade indicator (letters next to each other).
'guys and dolls fan' becomes 'bi' (bisexual).
'was'+'a'+'bi'='WASABI'
(Other definitions for wasabi that I've seen before include "'Japanese plant, often eaten with raw fish (6)'" , "Strong-tasting Japanese paste" , "Sushi condiment" , "Hot Japanese paste" , "Flavouring used in Japanese cuisine" .)