Think of it as both the stranger and the phone display pointing you in the direction of side girls, as opposed to nuts in the grass, an item in the outskirts, an item in the church, etc. That's six places to look instead of every area in the game.
Not only that, but the six girls are gathered in only three locations. So, three small-ish places to look.
When I first looked at the menu for a sign of what was still needed to unlock I didn't see it. Guess I should have looked harder, having played ToN and TGO through development I knew about those indicators, but didn't see them here, thinking they weren't there yet. So I guess I didn't thoroughly review the menu.
My point being that I didn't know those hints were side girl scene related. All I knew was that after I finished the main story, the oracle was telling me I had finished the update but had missed side things. So using the strangers I first got the pieces for the seed of strength. (I should mention that I hadn't played in a few updates, I think I only played the first one, so yesterday I started from scratch.)
So I was getting the scene hints, along with the item hints until I whittled it down to just the two scene hints, but I didn't know they were just scene hints (since I hadn't found the indicator in the menu that I had two "karma pages" like things left.)
so tl;dr, I had no way of knowing they were pointing me to side girl scenes from the newly acquired strength, so it was the whole map not just the three locations.