Make me fall in love again!

I was summoned to another world one day after repeatedly confessing to my childhood friend and getting rejected. When I returned, that passion had completely disappeared... Wait! And now the "Demons" that were supposed to have been annihilated in this world have infiltrated it!? I can't even casually pursue a new romance! So it's that kind of story where a brave heroine gets physically buff and the guys are like "Kyaa! Help me!" Sorry, the second half is kind of a lie. It's actually a fairly serious battle story, but the romance elements fade and then intensify again.