Dragoon - Extra: Mystith is Working Hard

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----

A short, happy, and heart-warming story about the daily lives of a modern-day married couple.

The Empress who dies in torture, An Rushuang is her name. After she wakes up, she finds herself has time-travelled to when she was twelve years old, but she would turn into Major General’s white horse at night. He is a general who orders about the winds and clouds on the battlefield, and she is a little girl lives in her boudoir seclusively.
She endeavors to change her fate, and he spared no effort to win every battle. They meet each other every day, well, it’s night to be accurate. Is that a dream or not? She pleads to marry the seignior to win peace for her family, only to find he is the one she is going to marry.
“Growing old with you under the same roof is my long-cherished wish”, thought them both.

- Description from Novelupdates

A boy awakens alone in the Fairy Tail world, lost and uncertain. As he ventures through this magical realm, he unravels the secrets of his mysterious new identity, unlocks hidden powers, and carves out his destiny in a land brimming with wonder, danger, and limitless adventure.“Check out my other work, Reincarnated as Ash: A Pokémon Tale.”