Cursed Escort Side Quest - Persona 2: Innocent Sin Guides
The Cursed Escort Side Quest begins immediately after you complete the Cursed Taxi Side Quest. Both of these quests can be started by speaking with Fuyuko inside of the Peace Diner in the Yumezaki prefecture. Once you finish Cursed Taxi and turn that quest in Fuyuko will tell you that you defeated the wrong boss and you're looking for a different enemy.
Fuyuko will give you another rumor, this one for the Cursed Escort. You'll want to spread the rumor then head over to the Abandoned Factory to take out this guy. In my experience you can only encounter this enemy in Room 3 of the Abandoned Factory so search around in that room until you get into a random encounter with the Cursed Escort (shown below).
When you defeat this enemy he will drop the Yacht Hat item which you'll want to return to Fuyuko for the reward. You're rewarded with a Sacrifice Card for completing this quest.