The First Mythical Dragon: Harem System - Chapter 15: New Skills!

Suddenly a high school student Subaru Natsuki has been summoned to another world on the way back from the convenience store. With the biggest crisis of his life being summoned to another world and no sign of the one who summoned him things become worse when he is attacked.

The plague of insects descended overnight. As an ordinary person without invincible powers and extraordinary exercises, facing blood and death, what should we do at the critical moment of life and death?

(I am a reasonable party, but the novel needs appropriate YY, please do not excessively investigate the rationality of the background in a razor-sharp way.)

- Description from novelbuddy

Setsuna Shū is a magical girl with temporal magic that allows her to go back to the past whenever she performs a certain action. She works as a magical girl, hunting monsters and helping people… or at least, that’s what she lets everyone believe. In truth, she made a contract with a demon so she could return to the past and rewrite the future.Her real reason for turning back time is to save her “sister.” As a child, she had no parents, relatives, or friends. When she was finally adopted, her sister became her entire world — and for her sake, Setsuna wouldn’t hesitate to sacrifice the world itself. She gave up her original gender, her past “existence,” and even parts of her freedom in a demonic contract, all for the sake of saving her sister and taking revenge on the monsters that hurt her.But… is that really all there is to it? Or is Setsuna, in the end, partially responsible for everything that happened?

“Legend had it that in the deepest part of the oldest galaxy, there was a door as red as blood and fire.

Legends and myths, darkness and light, countless stories passed through this old door.

The Door of Constellation that overlooked everything would warn the sky and earth, sending darkness back to where it belonged.”