Would you like an otaku girlfriend? Obviously the answer is NO, But...

She comes to school only 3 days a week, has a sickly body, is smart, super popular, and is a cool beauty, shes "mysterious heroine" Shiraishi Yuki.

And an "ordinary protagonist" Sakai Haruhiko, nothing stands out about him and hes a harmless guy who does not seems like a protagonist at all.

The heroine that the protagonist fell in love without knowing anything, is actually a super closet hikkikomori otaku!!

Thus, this is his story to understand her hobbies, while walking in the thorny otaku path.