Approach unfinished story that's similar (10)

'similar' is the definition.
(I've seen this before)

'approach unfinished story' is the wordplay.
'approach' becomes 'come' (e.g. as imperative).
'unfinished' means to remove the last letter.
'story' becomes 'parable' (parable is a kind of story).
'come' with its last letter taken off is 'com'.
'com'+'parable'='COMPARABLE'

'that's' acts as a link.