Manami is asked to cook for everyone (it's the mothers day off), sending Kirino in a jealous fit. She immediately equates her coming over with copulating in the living room - a perverted mind for sure. Since Manami wants to avoid any fighting she offers to be essentially a slave for a day - and is promptly ordered to clean the living room before making lunch. Afterwards she fails to find any serious faults, not for lack of trying, she goes back to her room to out and scheme. She actually plants her laptop with an eroge on it in Kyousuke's room. While he is busy trying to hide it and the game (why not close the lid?) Manami finds the porn magazines planted on his bed. That plan (as well as Kyou's new imoucon screensaver) backfires though, because Kyousuke apparently has a megane fetish and Manami is the most subservient girl ever. She even offers to call him Onii-chan from now on.
After the A-part concludes on that note the anime jumps to Kyousuke making his way to "Kirino's Anime Celebration Party". Saori organised it in a love hotel and reserved the rooms under Saori Vageena (yes, it is pronounced like what you're thinking), much to Kyou's dismay. Not as much as the giant sign saying "Kousaka Kyousuke's Personal Harem" though. Once he enters the room he is greeted by Saori and Kirino in maid cosplay and character. Well for a few seconds, at least. :P Kuruneko is also there, having spiced up her uniform with nekomini accessories. Enough to catch his interest, it seems.
Anyway, each girl had to prepare some entertainment and the maid outfits were Saoris turn. Kuruneko continues with a manga bearing uncanny resemblance to the actual cast of the anime, right down to Kirino's brother fetish. Sadly it is cut short after a few pages, because the tsundere imouto intervenes.
She is embarrassed, so some small-talk is used as a gap filler. During that Kuroneko adopts an imouto role and comes on to Kyousuke, sending Kirino in another jealous fit, just like she planned. That final fit of anger puts Kyousuke over the edge and he rants how he's been depressed and how his sister is ruining the party. This in turn triggers her to start her entertainment part - consisting out of her giving him a present, apologising for her behaviour, thanking him for all he did, and finally opening up. Kyousuke is shocked. He then starts to cry and we get an insight into his feelings once more: He's basically the perfect brother and undercover imoucon.
By the way, the present is an eroge.
