Guy gets reincarnated in Naruto. as the title suggests, Obito did the "deed" [not with Rin sadly] with a random oc uzumaki and forgot to pull out. 

ts is translation, so yea it is of chinese origin

it is f/m, kind of Obito redemption? looks to be a single female lead as far as I have read.

This book aims to offer a different perspective on Uchiha Obito 

My name is  Rubik Uzumaki, and I am a transmigrator born in a small village in the Land of Water.
Although not a noble old Konoha resident of the ninja world, he lived a pretty good life. Thanks to his foresight as a transmigrator and his bloodline from the Uzumaki clan, this was a decent start.
Although his black hair and family traits aren't very obvious, he still has a lot of chakra. Even if he fails in his struggle, he can just go to Konoha and rely on Naruto to win until the end. There's no need to panic! The future is bright, win!
It wasn't until I was seven years old, when my mother, Uzumaki Something, was critically ill and bedridden, that she told me my father was a mysterious person wearing a white vortex mask. I looked at my Sharingan eyes, still shedding tears, in the mirror, touched my prickly spiky hair, and my mind went blank.

"Eh?"

Found out another guy is translating the same novel on this site and is also 100 chaps ahead of this, so I am dropping it


Chapter 55 - Tn