Fuminori Teshima 
An Archdemon’s Dilemma: How to Love Your Elf Bride (Manga) Volume 11 [EPUB ebook] 

Having learned the truth of her origins, Nephteros flees from Archdemon Bifrons. While being pursued by a chimera into Zagan’s territory, she has a fateful encounter with Angelic Knights.

Meanwhile, Nephy and Zagan have finally confessed their feelings to each other, but neither of them have any idea how to act like a normal couple. After getting some much-needed advice, Zagan learns of a mysterious event know as a “date” and goes on a research trip in town.