this ep mostly corresponds to chapter 4 of volume 4. in fact I found the anime to be funnier, perhaps I wasn't really savoring the hilarious moments in the novel.
the last life consultation (since she thought she was leaving for America and this would be the last): ask her brother to buy an eroge at a midnight launch.
eroge's title was a win: "I definitely won't steal something like my brother's underwear!!"
wwwww
Kyousuke asked his friend Akagi to cover up for him (Kyousuke was supposed to stay overnight at Akagi's house, while in truth he was going to get that eroge at Akihabara), and Akagi agreed, thinking that Kyousuke was going to be with Manami the whole night.
So they met each other at the launch and Akagi was supposedly getting homo eroge for his middle school sister; a nice inner self-tsukomi here by Kyousuke
www
Kyousuke got home with the eroge; Kirino asked him to play it with him since it has been a while(again this action was evident in the end because she thought she was leaving for America). From here on, things diverge.
anime: Kirino revealed, albeit unintentionally that she would be leaving for America the next day and studying overseas till she finishes high school, after getting scouted by a famous coach for track and field. to cut the story short, though Kyousuke did not stop her, she decided not to go. ~ THE END ~
not sure whether to post the difference since it's coming out in BD/DVD, and extended to volume 5, which makes sense, but I'm sure people can ask at the LN thread or through PM
