Call...Boy.
What a great wingman of a sister he has though, basically giving him the keys to a personal harem and also helping out all her Senpais with stress relief...But I guess she's technically getting paid for it?
The "No Sex" rule may have been a bit of a misstep as a wingman, but I guess they didn't let something like that stop them after he caved once.
Great ending though. Well hey...That's one of the better ways to go, I suppose. Besides, if he's a true Hentai Harem Protagonist, he should be able to handle this much...And his sister, too, if she joined in!
In no specific order: On first page and based on the hairstyle, I thought "Riku" was actually a girl - not this time, it turned out. * Rumi-nee has established herself as "Wing-Woman Of 2020" (we'll see if anyone can surpass her) * It seems Rumi's senpais are aware of "the call boy plan", but it's probably a matter of time before the whole dorm finds out, and everyone there (maybe including the dorm-mother) reveals that they're thirsty for Riku * As might be expected, one who got 'penetration' leaked the news to the others, so they all came to administer *koff-koff* "punishment" upon Riku.
"THIS ... IS ..... PUNISHMENT?"
As long as Riku can avoid "Death By Snu-Snu", he may well end up with a harem of "Sexy Onee-Sans" ... but I guess we have to stay tuned to find out whether that will be the case.
In The End, Matsukawa-sensei's latest offering is ... what else ... "APPROVED!"