Overlord: Welcome the Birth of the King - Chapter 50 - : The Half-Month Impact

Before going to college, an ordinary high school student went to celebrate and got drunk. When he woke up, he found himself in a completely different world. There was a big sect, the approaching sect entrance examination, a slum where his body’s previous owner lived, and a shared memory about a missing young girl.

Xia Yan passed through to the world of Bleach and became an eleven-year-old boy. He was rescued by Renji and Rukia in the Seireitei, and he was studying at Shin’ō Academy, and he was a student of the same class.
He is a top student of the Shin’ō Academy, and he is vying for strength by various teams. In the end, he has entered the first team of secret mobile maneuvers.
He will use punishment to kill every person who tries to threaten the martyrdom and protect his loved one.

- Description from Novelupdates

For his sake, she was willing to abandon her career as the best actress and be his wife. With her own network, money and unscrupulous methods, she helped him rise to the top of the world. He, on the other hand, held another woman in his embrace and kicked her away with no mercy. It turned out that all he ever wanted was her rare blood type, her six-month-old child’s cord blood. It was her life… When she opened her eyes again, she returned to her 20-year-old self. Time repeated and her life rewound. In this life, she would live well.

He—an enigmatic and cold-blooded soldier with a mysterious background.
She—a ruthless and bloodthirsty spy.