Naruto System in One Piece - Chapter 29

The Descent of the Dragon Tower.A young man refines the nine Dragon Emperors, cultivates the invincible Dragon Body of eternal glory.Slays the emperors of myriad heavens, gods, and demons alike, defying gods and Buddhas.Invincible across nine thousand realms!

After coming out of a tunnel… it was pitch dark.

After choking to death on a watermelon, Rong Jiahui thought that she would enter the netherworld and be reincarnated.

But when she opened her eyes, she discovered, to her very horror, that she had returned twelve years into the past…

Looking at the beautiful and awkward “little brother” that would be conferred the title of Marshal in the future for outstanding military service, she almost let out a snort of laughter.

She firmly decided to hug the thigh of this little brother, and climb to the top of her life!

The plan was beautiful, but it had just one problem.

Why had this little brother… suddenly turned into…

A little sister…

- Description from Novelupdates

Gu Zuo: Are you sick?

Gongyi Tianheng: You have medicine?

Gu Zuo: You’re sick!

Gongyi Tianheng: If I say I’m sick, can you cure me?

Gu Zuo: If I say I have medicine, would you want it?

Gongyi Tianheng: However much you have is how much I want.

Gu Zuo: However much you want is how much I have.

Gongyi Tianheng: Then bring it all out.

Gu Zuo: …

Simply speaking, a scaredy-cat shou transmigrated and had to think of a way to survive. He had a golden finger called Medicine Refining System, but unfortunately, he didn’t have the ingredients needed to refine medicine and level up.

A great young master to an Empire’s preeminent Clan had a super high IQ, but his talent for cultivation was low. Unfortunately, pill refiners were too hard to develop, and weren’t restricted to his personal service. But he could acquire plenty of ingredients.

Two people, one was sick and one had medicine. Therefore, the one who was sick kept the one who had medicine, and everyone was happy.

- Description from novelupdates