Season 1 of Last Waltz ~백탁 투성이의 여름 합숙~ premiered on April 30, 2010.

Mochizuki Yuuki and company are cut-off during a trip to an island training camp when civil war erupts. Just as the ship carrying the teachers leave to summon help, it is attacked by unknown persons and sunk.

With nobody to rely on and provisions dwindling, the survivors split into factions and must look to their own survival. In return for the boys' protection, the girls are subject to all manner of disgrace...