Naruto: The Outsider's Resolve - Chapter 4.28 (128):

The mountain village boy accidentally got the fairy gourd, and he rose step by step to cultivate immortality and longevity.

Ripe elixir, mortal flow.

- Description from novelbuddy

When I opened my eyes, I was inside a novel.

Yeon-woo had a twin brother who disappeared five years ago. One day, a pocket watch left by his brother returned to his possession. Inside, he found a hidden diary in which was recorded “By the time you hear this, I guess I will be already dead….”

I am a holy knight. To be precise, I am the Church of the God of Light’s Sun Knight…in training.

The Church of the God of Light worships and serves the God of Light, and theirs is one of the three largest religions on this continent.

As the whole continent knows, the Church of the God of Light has the Twelve Holy Knights, and each one has his own unique personality and features.

To be the Sun Knight is to have shining golden hair, sky blue eyes, a compassionate nature, and a brilliant smile.

…even the Sun Knight-in-training is no exception.

The 38th generation of the Twelve Holy Knights have completed their term of office, yet the time for the 39th generation to take over is still far in the indefinite future.

The Judgment Knight is brash and easily angered; the Storm Knight and the Leaf Knight are always fighting nonstop, day and night.

Since childhood, the Sun Knight-in-training has watched the others grow from kids into adolescents.

What must he do in order to become comrades, who will fight through thick and thin for each other, with this group of “younger brothers”?

“Benevolent God of Light, may I ask when I will complete my training that has taken more than ten years?”