While visiting Gallia, Perrine learns that children cannot get to school because the bridge is broken. This preoccupies her, as she even thinking of selling the last family heirloom to fund the bridge's repairs. On a training trip at the beach, Lucchini finds a treasure chest, which Perrine salvages in the hope of finding treasure. After going through an endless number of chests, they find a puzzle chest containing a map, which Perrine, Yoshika, Lynnette, and Lucchini follow to an underwater cave filled with booby traps. Meanwhile, while looking for them, Mio and the others encounter a trap which causes Mio to become drunk, kissing Minna and running off. Perrine's group soon comes across a room with a statue, which Perrine defeats when it attacks them. They eventually find the treasure, which is nothing more than a herb and spice garden. However, a slightly hungover Mio reassures Perrine that it is the feelings that people truly treasure. After returning to base, Perrine receives a letter from Gallia informing her that the children worked together to build a new bridge.