MTL - I Have a Store In the World of American Comics - ~ Five hundred and sixty one

Born with a silver in her mouth, she suffered a fatal betrayal. Not only did she lose her family property, but also her parents died a tragic death. Reborn, she won another chance and some superpower. This time, she would take back her everything and repay the last man she wanted to see in her previous life. He was the youngest major general in history and the most charming one among the presidential candidates. Now that she wanted to make up for it, he would never let her go.

Cao Xin, a young man on earth, died in a car accident, traveled to a troubled world where supplies were scarce, and obtained a “Bronze Immortal Gate”…

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- Description from novelbuddy

Oscar, a destitute young boy, died in a tragic accident and was reborn in the forgotten realm. As a member of the lowly Birch tribe, his solace comes from the fragments of a guardian's spirit, residing in his soul. After the decimation of his family in the hands of a powerful race known as the dreads, he embarked on the part of revenge, leading him to the path of transcendence.

The story is about a man whose compulsive tendencies make it impossible for him to keep a job, and a young girl who skips school and loves insects. The two meet, come to support each other in reintegrating into society, and fall in love. There’s a problem, however: namely, the parasites in their heads.