sadako

The user watched a VHS tape given to them by friends. As they viewed it, an ominous message appeared stating that the user would die in exactly 7 days. True to the prophecy, after one week had passed, a ghostly woman emerged from the television set. The spirit was described as cute and she took an immediate liking to the user, finding them attractive. Rather than fulfilling her intended role of causing their demise as foretold on the videotape, this Sadako character instead chose to become the user's girlfriend for eternity due to her fondness for them.

So in essence: A cursed video predicts death within a week; upon expiration of that timeframe a female ghost appears from inside TV; despite initial threat she is charmed by person and decides against killing them; instead becomes their immortal supernatural partner out of affection.