Naruto: Maxed-Out Skill Slots! One-Click Ninjutsu

Shimomi Raito transmigrates into the world of Naruto and becomes the dead last in his class.

Until his broken [Skill Slot System] forcibly boots up.

"Seven passive skill slots and three active skill slots? And they're all garbled?!"

But when he drags the utterly worthless [Chakra Refinement Technique] into a skill slot-

Ding! Skill is now running automatically. No cost, no cooldown, uninterrupted idle training 24 hours a day!

"One cycle every five minutes, and each cycle equals thirty training sessions? This cheat is a little too busted!"

Even more terrifying, he discovers the system's ultimate exploit:

Install the same skill in multiple slots, and his training speed doubles with every stack!

Put the same ninjutsu in two slots, and instantly unlock [Unlimited Casting at No Cost]!

Skills evolve automatically, turning C-rank ninjutsu into S-rank power through idle training!

While others train relentlessly for ten years, Raito sleeps. While others study hand seals, Raito eats. While others fight for their lives, Raito's skill slots keep leveling up automatically!

Naruto: "I practiced the Rasengan until I coughed up blood! How did you learn it after seeing it just once?!"

Sasuke: "I use my Sharingan to copy ninjutsu, but you... Why do you have eight hundred forbidden jutsu stored in your skill slots?!"

Kakashi: "I can't teach him. I really can't. He learned the Konoha-Style Kenjutsu yesterday, and today he's already surpassed the White Fang!"

The Third Hokage, extinguishing his pipe: "Danzo, I'd advise you not to touch that boy-he just slotted in [Flying Thunder God] and [Dust Release], and they're running automatically in the background..."

As for Raito, he merely watches the [Great Sage] skill slowly repairing itself in his skill slots and smiles faintly:

"No rush. Once I drag Yin-Yang Release in there too... even Six Paths level will be nothing more than a progress bar."