L'arc en ciel du Sud de la 2-C. L'étrange île de Yokuno ! Les sept mers... !

All the students of 2-C go on Eri's cruise through the Pacific for their winter vacation. They eventually hit a reef and the engine breaks down, leaving them stranded. Hanai flies on his kite to an island populated by what seems to be a Mesoamerican civilization, featuring familiar faces.