Aki and Satsune. Aki as part of her idol training is putting on what is supposed to be clothed act at the club. Her mother is supposed to be watching with Matsu. Satsune is being a bit forward with Matsu in the audience, Aki notices and her act suddenly become a bit more R rated. Satsune gets on stage and instead of trying to stop it, tries to out perform her. Matsu then gets up to calm the situation, and ends up having sex with both on stage as they each try to outperform the other.Given the choice, who is a perfect threesome pairing, where is it taking place, and what naughty fun are you three engaged in-cause its a real shame to waste a perfectly good threesome on vanilla swapping on whose riding Matsu.
Bonus story: Saki is showing Kaede what she does to montor things in the club and they accidently stumble on a video feed of the incident. Kaede learns the truth about Saki, and her father and Saki makes it her mission to share Matsu with Kaede.