S1·E16 The memory that vanished into the sea

Even though he has royal responsibilities that take precedence over it by far, the prince Ayumi exerts a great effort to reconnect with his childhood friend Toshio who is practicing his soccer skills with Midori when Yuu arrives wanting to join in; Yuu is not as practiced in soccer as Toshio and loses control of the ball. Toshio's ball now in hand, Yuu encountering Ayumi sets the stage for a sequence of reminiscing before the sentries force the kids into a hasty retreat. Now at the wrecked ship, Yuu happily runs around exploring the ship with Midori on her heels before deciding to search for the treasure in earnest; things go sour when Midori inadvertently knocks the ship loose from its resting place where the waves can easily capsize it. Yuu finds Ayumi's treasure but is ultimately forced to forego it to save everybody as Creamy Mami when the ship begins sinking; as far as Ayumi is concerned, the opportunity to spend time with Yuu and Toshio is a far greater treasure than the gold statue he had intended for her.