Letter from the Land of Rain

Konoha Police Force, a laboratory that had just been cleared out and remodeled.

The light from the incandescent lamps fell upon the workbench, which was piled with Chakra Conductive Metal "moved" back from Root and all kinds of rare materials.

Namikaze Minato leaned against the workbench, curiously fiddling with a metal tube wrapped in copper coils.

"What are you researching?"

Nishikawa Tetsu wore goggles as he carefully handled a Lightning Nature Chakra crystal with tweezers.

He straightened up, his gaze turning sharp and fervent. "I'm using scientific thinking to deconstruct Chakra from the ground up."

"For example, this."

Nishikawa Tetsu pointed at the coiled device in Minato's hands.

"I call it—the prototype of the Lightning Style: Railgun."

"Railgun?" Minato blinked, finding the name rather cool.

"The principle is simple."

Nishikawa Tetsu picked up a specially made coin mixed with Chakra Conductive Metal seized from Root.

"Lightning Chakra generates a powerful magnetic field in the coils, then the Ampere force accelerates the projectile in an instant. Compared to bullets propelled by gunpowder explosions, this method makes no sound and no flash, and its initial velocity can easily exceed three times the speed of sound."

"Minato, give it a try."

Nishikawa Tetsu secured the device onto a stand and gestured for Minato to inject Lightning Nature Chakra into it.

Although Minato was not as proficient in Lightning Release as he was in Wind Release, it was more than enough for an experiment.

"Crackle, crackle..."

As Chakra flowed in, blue arcs of electricity lit up along the coils.

"Fire!"

Nishikawa Tetsu flicked the coin into the rail.

Boom!

An extremely brief explosion rang out.

The coin streaked through the air in an orange beam of light, plasma produced by its intense friction with the atmosphere.

Fifty meters away, a heavy steel plate used to test defensive ninjutsu was pierced through in an instant.

The cut was as smooth as a mirror, while its edges had melted from the heat.

"This..."

Minato stared at the hole, cold sweat trickling down his face.

"This is stronger than my Wind Release? And it's so fast that even the Sharingan might not be able to track it."

"This is only a prototype." Nishikawa Tetsu recorded the data. "If it could be paired with your Flying Thunder God and fired point-blank the instant you teleport... that would be an absolute killing blow."

"Besides this, there are also applications for Earth Release."

Nishikawa Tetsu walked to another corner of the laboratory, where several barrels of gray powder were stacked.

"This is the 'Special Chakra Cement' I developed by combining Earth Release Chakra Nature Transformation."

"As long as Earth Release Chakra is injected into it, this powder hardens within three seconds and becomes five times harder than granite. On the battlefield, it can instantly create an impregnable shelter, or..."

Nishikawa Tetsu narrowed his eyes. "It can be used to rapidly build defensive fortifications and completely seal off the enemy's line of attack."

"And there's Water Release."

He picked up a high-pressure nozzle covered in tiny Fuinjutsu formulas.

"The principle behind Water Style: Hard Vortex Water Blade is to create a water vortex, but mine is a 'High-Pressure Water Cutter.' Fuinjutsu compresses the water pressure to the limit, then fires it through an extremely narrow nozzle. This stream can cut through steel and is even sharper than Wind Release."

Namikaze Minato looked at the room full of "new inventions" and could not help swallowing.

"Che, are you trying to turn ninjutsu into a physics class?"

"Chakra is a universal source of energy. Using it only to spit fire and water is far too wasteful."

Nishikawa Tetsu removed his goggles and rubbed his brow. "What we need to do is create the greatest physical destruction with the least possible Chakra consumption. That is the true essence of Scientific Ninja Tools."

Just as the two discussed how to miniaturize the railgun for portability—

Poof!

A burst of white smoke exploded over the workbench.

A small bespectacled toad—messenger Kosuke—appeared out of thin air with a small package on his back.

"Yo, Nishikawa Tetsu, Namikaze Minato."

Kosuke adjusted his glasses. "A letter from the Land of Rain."

"Oh? Yahiko and the others?"

Minato's eyes lit up, and he immediately put down the parts in his hands.

Nishikawa Tetsu accepted the letter and opened it.

The paper was somewhat rough and carried the damp scent unique to the Land of Rain. The handwriting belonged to Yahiko, bold and flamboyant, though it was mixed with Konan's neat additions and Jiraiya's unrestrained annotations.

[Che, Minato, it's as if we're face-to-face!]

[Everything is going well here! Following the Business Plan you gave us, Che, our Penicillin business is unbelievably popular! It's not just merchant caravans—even nobles from several nearby small nations have been secretly coming to buy it. We've already used the money we earned to repair homes in three villages, and we've taken in even more orphans.]

[Oh, right, I'm Akatsuki's Leader now! Though we still have fewer than twenty people even with Master Jiraiya included, everyone's full of spirit!]

The middle portion of the letter was in Nagato's neat and forceful handwriting:

[Che, you were right. Power needs to be controlled. Under Master Jiraiya's guidance, I'm now learning how to control... that power. It's difficult, but I won't give up. I'll protect Yahiko and Konan.]

[Also: The compressed biscuits you sent last time tasted awful, but they were very filling. —Nagato]

Finally came Jiraiya's large, wildly scrawled writing:

[Hahaha! You two brats have caused quite a stir in Konoha! I've heard all about it—reforming the Police Force, raiding Danzo's old nest. Well done! But you still need to be careful. Danzo is no simple man!]

[How are Fugaku's eyes? Tell him not to overthink things and focus on recovering.]

[I'll be staying here a while longer. These three kids are growing faster than I ever imagined, especially Nagato... In any case, I'm leaving Konoha to you two. Don't worry about me. —The Toad Sage of Mount Myōboku]

After they finished reading, the atmosphere in the laboratory grew much warmer.

"Looks like they're doing well."

Minato smiled as he put the letter away. "Yahiko really is making his dream come true, step by step."

"Money, food, strength, and the right guiding principles."

Nishikawa Tetsu carefully stored the letter in a filing cabinet. "As long as they don't stray from the right path, Akatsuki will become a force in the Land of Rain that cannot be ignored."

"Oh, right." As if remembering something, Nishikawa Tetsu pulled out a bag from the pile of "cement."

"Minato, bring this along the next time you write back to Master Jiraiya."

"What is it?"

"The Improved Quick-Drying Cement Formula." Nishikawa Tetsu said, "The Land of Rain gets a lot of rain, the roads are difficult to travel, and houses collapse easily. With this, they can build infrastructure ten times faster, though the materials are a little expensive."

"Build infrastructure?" Minato did not know whether to laugh or cry. "Are you trying to turn the Akatsuki Organization into a construction company?"

"To get rich, build roads first."

Nishikawa Tetsu picked up the railgun prototype, rational light glinting in his eyes.

"We'll engage in political struggle and an arms race in Konoha, while they focus on economic development and surrounding the cities from the countryside in the Land of Rain."

"Though we are in different places, we are both striving for the same goal—"

"Ending this chaotic age."

Nishikawa Tetsu loaded a new coin into the coils.

"Alright, back to the experiment. We have to solve the overheating problem with these coils tonight. Otherwise, if Senior Fugaku uses this thing, he might roast his own hand before he kills the enemy. That would be a medical accident."