+α no Tachiichi

+α no Tachiichi (+αの立ち位置) is a manga series by Yuu Geni. It was serialized in Zero-Sum Online.

Plot
A female protagonist should be pure of heart, good-natured, and, most importantly, beautiful. Satoki Houma has accepted that she will never be that person.

In a bizarre twist, Satoki and her classmate, Haruka Toudou, are dragged into another universe. The denizens of this new world are searching for their savior: the "Holy Maiden," an otherworldly woman with extraordinary powers. Though they were both summoned, Haruka’s beauty leads to the assumption that she is the true heroine. Unbeknownst to them, Haruka does not possess the Holy Maiden's powers, but Satoki does not want to break the illusion.

Satoki does not mind being a bystander, concealing the truth from everyone—even Haruka. Believing herself unworthy, Satoki will do whatever it takes to make Haruka appear to be the savior the world has always wanted.