Sorry to Interrupt

In Blondie's case I wouldn't ever let the sister near the boy ever again. For reasons...

Despite the title, I don't think she was sorry for interrupting one bit.

This may be vanilla, but it's the bad kind, like that off-brand type of vanilla that just doesn't taste right, ya know, like they skipped out on the premium ingredients to make it more affordable type vanilla. 5/10

Tsundere/yandere two for one combo, anyone?

DAYUM! ... 'Onee-san' is rather savage enough to snatch his first time away from his girlfriend (her younger sister), yet in the end she *cough-cough* cautions him: "If You Do Anything To Make Her Cry, etc ..." - BRR! And girlfriend agress with it.

Does that make you a "Lucky" or "Unlucky" Bastard? You Tell Us one day, Tsukasa-kun ... You Tell Us.

"We're sisters, aren't we? Why can't we share boyfriends"? Looks like she certainly understands her Hentai logic...
Hmm, the way her sister just kind of...pushed her aside when she was trying to insert it was quite interesting, I must say.
Certainly a thoroughly entertaining release, if only because of the interesting relationship the sisters share.
Great ending though. I guess she herself is the only exception to that rule? So basically, he isn't allowed to cheat except with the sister, how nice.