One Piece: New Order - Chapter 32: Shandora and Birka

After forming a blood pact with the Saint and Demon ladies, the good-for-nothing young boy obtained the Yin-Yang divine veins, learned the art of alchemy and martial arts, and dominated the world.The young Shen Xiang had a romantic encounter with a goddess and a witch, and obtained their supreme inheritance, acquired a divine vein that defied the heavens, learned peerless magical skills, and mastered superb alchemy techniques, which made him very successful on the road of martial arts... When he was hungry, he would refine some pills as snacks, when he was lonely, he would flirt with the high and mighty goddess, when he was bored, he would play with those martial arts masters who came to ask for pills, and when he was tired, he would let the delicate wives around him give him massages...

The genius pharmacist transmigrated into a pitiful farm girl’s body. Ignored by her own father, abused by her stepmother, and bullied by her stepbrothers. Her “twin” brother was given to distant relative and she went as the “extra” to live under someone else’s roof.

Luckily she possessed mad apothecary skills. Collecting herbs, plowing herb fields, formulating medicines and treating the ills, she refused to live an ordinary life as she slowly uncovered the truth of her real identify.

Inadvertently, she saved a dashing man who was in reality a big, bad wolf hiding under the skin of an innocent little puppy. He pulled out all his tricks: I have no other means to return your favor of saving my life. What say I repay you by marrying you?

- Description from Novelupdates

Set on a giant, almost finished bridge between Sadogashima and Niigata. Abandoned by the government, the bridge, and the giant man-made floating island at the center, has become a city of criminals and societal drop-outs.

Set in the same world as Durarara, but 15-20 years later. There is almost no overlap between Etsusa Bridge and the other novels.

The ordinary 18-year-old Edo, during a nighttime walk, finds himself in a fantasy world where he gains a mysterious power that could shape his destiny.