City Environmental Sanitation System

The first step to getting rich is to build roads.

This could be called a universal truth.

Beneath Konoha Forest lay a complex underground network, painstakingly excavated by Mimi day after day.

In the early days, before there were any effective underground detection methods, Mimi could only keep her head down and dig. She used the Cross Fishbone Excavation Method, an upgraded version of Cross Excavation.

That meant digging a mining tunnel from a single point deep underground in four directions, forming a cross.

The Cross Fishbone method took this a step further, continuing along the tunnels and opening several more passages in a cross shape.

This was an extremely efficient method of manual excavation.

It allowed her to search for underground resources across as wide an area as possible. What she managed to dig up depended on luck.

The advantage was that she would not get lost as easily as she would in certain underground mazes dug at random.

At times, she also used Blasting Excavation.

Later, once methods such as Sonic Detection had been perfected, she gradually abandoned this blind digging method.

Mimi backfilled most of the useless, abandoned mine tunnels. Some were preserved as transportation routes for the insect swarm.

During this period, Mimi first conducted a surface survey. Once she located an ore deposit, she would drop a Tunneling Insect split body at a fixed point above it. The split body would use the Straight Tube Method to drill vertically downward.

This was also called the Shaft Method, and its construction was simple and brutal.

Methods such as the Ladder Method and Spiral Ladder Method were more difficult to construct, but made extraction easier and facilitated transportation to the surface. However, they were easy to expose, caused significant damage to the surface environment, and created serious