I am, Flame-Chaser of Previous Era - Chapter 78: Sakura

Kurokawa Risa is an ordinary office worker, who has practiced lots of cooking while living alone. One day, she wakes up in another world, with a concerned little spirit hovering over her! She has apparently been transported to a magical, spirit-filled realm by the will of the goddess, and there is no known way for her to go back. She is taken in by a wealthy couple, and they and her new spirit helper treat her with nothing but kindness. There is one problem, however–the food in this magical world is gross! Risa insists on helping the household cooking staff prepare a traditional meal from her world, and it is a big hit with her hosts. Soon Risa knows what she should do in this new world; she should open a cafe and treat everyone to delicious food!

“I can’t do it anymore. Stop it…I can’t take it anymore!” The second young master stopped in his tracks and raised his brows as he stared at Miss Jiang. “All you had to do was jog, so—”

Everyone knew that Miss Jiang was an artiste who had been defamed and blacklisted before she became famous again. When she got into trouble, she did not give up but fought persistently. Everyone knew that the second young master was the mysterious head of the enterprise. He was an extremely cold person with an exquisite taste. Moreover, the second young master had recently adopted a new hobby. He took in his younger brother’s ex-fiancée and he was extremely fond of her…

- Description from Novelupdates

Sato Yu is a 12-year-old boy. He is a deprived person. His life is depriving. His step father has a large amount of debt.

The story is about a a hitman, Who dies because of his own recklessness and transmigrates into a game he used to play after his retirement as a hitman.I'm not gonna spoil any further, but i might answer few of your questions.Is MC overpowered?Nope, he'll become strong over time and all battle he'll fight will be because of his effort and techniques.Is there magic and adventure?Yes! It have both magic like normal isekai with adventure and fighting with monsters and many other things. There are other important things like “Essence Stone” But let's talk about it in the chapters.There will be harem?Not really, He will be in contact with many beautiful female and males but one waifu but i haven't decided yet.All i can say is, give it a try, I'll try my best to make it worth your time.