Let's see which quints fits with what was shown from Lolikano.
Pros: extroverted leader that isn't afraid to approach him; smile with teeth
Cons: seems to not remember him + surprised reaction from the photo
Pros: subconsciously attracted to the blond boy and familiarity
Cons: no direct recollection
Pros: most likely to be left behind by the others; good observer from the shadows; addresses him immediately without honorifics
Cons: doesn't seem to recall anything and no reaction to the blond wig
Pros: helping someone in need; putting in more effort for her sisters; typical Yotsuba smile
Cons: doesn't seem to recall anything; too honest a character to keep this a secret
Pros: known for wanting to be a good example for the others in lieu of her mother, "five" time the effort, Itsuki says practically the same thing in the hospital
Cons: doesn't seem to remember him and whether she bought the charms; doesn't act or change her approach towards Fuutarou after the Rena incident
Me personally I would rule out Ichika and Itsuki.
For me the order of likelihood according to my guts wood be