The last "romance" is with Julie, whom you can gift a Hibiscus Bouquet, a Plumeria Bouquet (Both from Melia's Leis and Flowers on Downtown Street), and some Hawaiian Cosmetics (From Seaworthy Treasures on Waikiki Street). Once you do all of that and have upgraded her workshop's level to the max, she'll want to put something she's read into practice with Ichiban.

As poor Ichiban's body becomes Julie's plaything, he will at least get a boost of 5 points to his Agility, that's something! She'll also become another Dondoko guest.