Saiko no Nijigen Yome to Masaru au Hoho.

is a Japanese light novel series written by Ashiya Rokutsuki, with illustrations by Takehana Note. The series began publication on May 10, 2018 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
After all two dimensions are the best. I mean, I only have two dimensions!

It's different from those who say they like 2D and have a real girlfriend, or who say "○○ is my daughter-in-law!" And change their daughter-in-law every season. I ... I really love the 2D character "Walnut Spika".

One day she appeared in front of me, focusing on the ritual of love for her as usual. She is, of course, Walnut Spika-chan!

It's not a dream or a delusion. It's a monophone. It's a three-dimensional thing that you can even press your face against your pants. No, even if I wanted to, it was scary and I couldn't do that ...

What should I do with my longing girlfriend in front of me !?