Spoiler
If you talked to Kent and triggered the event, you can proceed with the quest for Blond Girl (called 'Mariko' or 'Faith') at any time. All you have to do to do that, first catch a ghost in Evergreen and stay in a place other than the first floor stairs for about 20-30 minutes and wait for Blond Girl and two men to show up. If you have encountered them, you need to meet the Blond Girl of the past in front of the warehouse through the portal and proceed with the quest, as I posted before. This is how to proceed with the Mariko quest.