Alice+Phi B - B Dio (3+1 / 6)
Luna+Clover B-A K (4+11 / 6)
Tenmyouji+Quark B-A Sigma (11+11/1)
Sigma claims that Tenmyouji has broken his promise to ally. Tenmyouji responds that it was Quark who made that promise, and he had nothing to do with the betrayal. Tenmyouji also promised not to open the number 9 door, but he doesn't need to - Clover is opening it.
Tenmyouji, Clover, and Quark prepare to escape, but before they do, Quark hands Sigma a letter about Tenmyouji.
The letter describes Tenmyouji and Quark's life on devastated Earth, where Tenmyouji lives by salvaging scrap from abandoned buildings and removing anything useful from it. Tenmyouji and Quark fell out on one occasion, but Tenmyouji tried to make amens by buying Quark a root beer float - a hugely valuable item, as root beer is more expensive than even the very best alcohol, and something which Quark had never thought he'd see. Quark decides to stay with Tenmyouji for the rest of his life.
Tenmyouji, Clover, and Quark leave, but not before Tenmyouji mentions that he knows, and has known for a while, who Zero Sr. is. Everyone else is trapped.
Although this ending involves everyone getting trapped, it is a useful ("END") ending rather than a Game Over.
On the PS Vita version of the game, getting this ending gives you the In Root Beer Veritas achievement, a reference to the phrase In Vino Veritas.