Tachibanaki Keisuke, a fresh-faced newbie just starting his journey as a full-fledged member of society. His company might not be a big name, but it is the job he'd always wanted, and life's treating him well.

But even with his go-getter attitude and eyes on the prize, living solo for the first time has him feeling a bit burnt out. That's when the thought hits him...

"Having a girlfriend wouldn't be so bad..."

One day, his younger sister Riho shows up on his doorstep, bags in tow. Turns out, their parents have been knocked out by the Norovirus, and with Riho's college exams looming, they've shipped her off to Keisuke's place for some healthy isolation.

Now, Riho's had her brother on her radar as more than just a sibling for a long while, and living under the same roof? Let's just say those feelings go from a simmer to a full-blown boil.

Keisuke, on the other hand, starts seeing Riho in a whole new light, not just as his little sister, but as a woman. Their relationship starts to blossom into something...

Beyond brother and sister...

[Based on MangaGamer]