The True Heiress is the Reserved Fiancé's Exclusive Memory - Chapter 600 - 612: Five Days and Five Nights (1)

A boy from 21st century Earth, met an accident and later was reborn in Naruto’s Ninja World.
He is born in Uchiha Family and becomes the useless brother of Itachi Uchiha and Sasuke Uchiha…. Let’s see how he changed the Naruto world.

- Description from Novelupdates

When a person dies, they either die light as a feather (aka unimportant) or heavy as Mt. Tai (aka very important).

A millennium had passed, and everything had lost its meaning in his eyes. Many heroes emerged from generation to generation, but he stood the test of time. That was his life, waiting for someone to come along and defeat him, but no one did. Nobody dared. Nobody tried.How can he allow this to happen? With the aid of his magic, he rose from his throne and set out into another world in search of excitement and, perhaps, a worthwhile adventure.What would happen if this last boss decided to venture into the human world for fun?

[Harem + Mature + Summoning + Diverse Races Harem + Upgrade]Negut has transmigrated, but this time, he never expected that his girlfriend would also come to this world.Not only that, his girlfriend has become one of the most terrifying existences in this post-Apocalypse world, where modern technology is combined with magic.Only having the F-99 rank class, Slime Summoner, the weakest of all classes?What is even more unfortunate is that because he had borne all of his girlfriend’s disabilities in their previous life, in this life, he is a cripple. One leg missing, one eye lost, and his lung function severely impaired.It is fine. Even if he is weak, as long as his harem is strong, that is enough.Blood Dragon - Lilith, Light Spirit - Tanila, The Thorned Seraph - Selviera, Technology Angel - Zariel...While everyone is envying him, he only wants to run away.Because a lemon is only squeezed once before being thrown away, while he is squeezed over and over again.