へっぽこ吸血鬼vs.最強の妹!?

From Author Wars - https://authorwars.com/books/hetsupokoxi-xie-gui-vszui-qiang-nomei-2462167.html

Overview:

Title: へっぽこ吸血鬼vs.最強の妹!?
Author: 藤孝剛志
Year: 2014
Type: Novels
Series: 姉ちゃんは中二病 / My Big Sister Lives in a Fantasy World
Number in Series: 2

Variant Titles:

2017. The Half-Baked Vampire vs. the Strongest Little Sister?!

Genres/Themes:

young-adult fantasy