Hitozuma Isekai Senshi Natsumi

Natsumi Takahata was just an ordinary housewife until the day she was overwhelmed
by a suddenly appeared ball of light and summoned into the alternate world.
According to a god of the world who summoned Natsumi, the world is currently
facing the risk of collapse due to the demon lord who also came inter-worldly.
Nothing but Natsumi's sword has a chance to defeat the demon lord.
In order to get back to her original world, she takes the sword in her hands.

[From DLsite English]