The Sixsome is a household, created by BlankyXP in the Sims 3.
The household consists of six members: Naomi Young, a professional writer, Dominick Hawthorne, a scientist, Ash May, an insane old man, Connor Briar, the young prodigy, Cynthia Lane, a well-renowned rock star, and Mia Wong, a chef. The six live together, generally peaceful and happy with their lives. The house is a bit cramped at times, but they've learned to live with it.
Connor and Dominick, and Cynthia and Mia share rooms together. Naomi has her own room, albeit it is very small, as well as Ash, whom sleeps in a cozy corner of the attic.