Karen Ayanokouji, Jun'ichi's classmate, invites him and his class to her casual "home" party. He is at first not interested, but is dragged along by Minato who also receives an invitation. When they arrive Jun'ichi, Yuuhi, and company find that the party is actually a formal event on a huge cruise ship. Seeing how underdressed everyone is Karen loans them some formal wear, and Minato makes quite the impression on Jun'ichi when he sees her with her revealing dress...