Months before the world tree grew in Hart's mansion...
The drain in the mansion's bath was broken.
Usually the water in the bath is released into a river that flows nearby as sewage after passing through the septic tank.
But the broken plumbing caused the water flowing out of it to flow out somewhere.
Tina, entrusted with the management of the mansion, headed to the basement of the mansion to examine the impact.
In the basement of Hart's mansion there is a warehouse that stockpiles ingredients and more.
The water flowing out of the bath had not come to its storage warehouse.
"... In the meantime, the ingredients are safe"
Having confirmed the safety of the ingredients, Tina then opens the door in the storage warehouse, descends the stairs that lie ahead and heads further underground.
A vast space exists more beneath the stockpile warehouse in the basement of Hart's mansion.
This is a space created by Tina in dirt magic for Hart to train in magic.
Tina is that someone has been reincarnated into Hart's flesh. And I was realizing that he was hiding from Tina and training in magic.
Tina was willing to wait until Hart was willing to tell her a secret she couldn't reveal.
She hoped that Hart would be a brave guardian. I was hoping.
But I was afraid to confirm that.
I waited for him (...) for a hundred years.
So there's no need to rush any further.
I'm sure he's just reincarnated and his memory isn't stable. Something prompted me to think about myself - that's what I decided to think.
So Tina created this space under his mansion so that he could sneak magic training even after he enrolled in the School of Magic.
Of course, there are multiple defensive magics on the walls and ceilings to prevent him from being buried alive by any kind of magic.
A very rugged underground space created by the world's most powerful magical swordsman, Level 250, is complete today without the Transfer Brave.
In the end, however, this space was never used by Hurt.
In my first class at the School of Magic, it was because Hart used his magic with all his might.
In a (...) le (...) Tina realized that Hart was no longer going to sneak up on magic training.
─ No, maybe he was willing to do some sneak magic training.
Even so, Tina can no longer let Hart use this space.
Because Hart used the magic of the power to gently erase Tina's defensive magic.
For his safety, Tina didn't tell Hart about this space.
─ ─ ─ ─
Tina was also carefully waterproofed as there was a risk that the underground space would be submerged if there were a rain leak or an influx of groundwater.
Normal rainwater and groundwater therefore did not invade this underground space.
But the water drained from the bath of the Ernoll family was not just water.
Hot water warmed by May, with the power of the Spirit King class, using the original flame.
When Saira, with the power of the Virgin, enters it, the potency of holy water is conferred on the hot water.
Furthermore, the mixing of the bodily fluids of the Nine-Tailed Fox, the Dragon Nation and, at the end of the day, the Demon King transformed them into hot water capable of storing vast amounts of magic.
This hot water, if the person lacking magic enters, will restore all magic, but when the person with excess magic enters, it was a thing that could store as much magic as possible.
In such hot water, under the influence of a stature fixed by an evil god, if a halt with infinitely equal magic...
Any injuries were healed, the lifespan was extended, and some amazing hot water containing a tremendous amount of magic - "Awesome Water" was completed.
It is no exaggeration to call this awesome water, the best item in the world. Such tremendous water was poured into the sewage the next morning at the Ernore family.
However, the broken drainage plumbing in the bath caused Awesome Water to flow into Tina's created underground space.
Awesome water slowly eroded the underground space, which was waterproofed by Tina's earthly magic.
As a result...
"Is this Orihalcon? This is Adamantite. And Demon Ore... What, could this be..."
The wall in front of Tina shined in the same color as the ring she would put on her left hand pharmacopoeia finger.
Hihiilocane called immutable metal.
It's a super rare ore. There are dozens of kilometers, even just the part where you can see it.
The erosion of her underground spaces had transformed all of her walls into a wide variety of rare ores.
If the rare ore in this space could be mined, any arsenal would be capable of production.
The H&T Chamber of Commerce, run by Tina, also owns more than one mine, but not more than half of the amount here, even if all its mining is combined.
In particular, I had never even heard of its existence, as opposed to owning a mine or other mine where Hihirokane could be mined.
Moreover, in this underground space, all the ore is protruding. I hardly even need the hassle of mining.
The place where the leftover water from the bath came in was an all-you-can-take space for treasure.
─ ─ ─ ─
Time moves on, today.
Suddenly, a giant tree appeared in the mansion's courtyard.
"No way..."
Tina was overwhelmed by the presence of the giant tree, a little relieved, then noticed something and hurried to the underground space.
The underground space she created was located directly beneath the courtyard.
"Oh, did this happen after all..."
I had a bad feeling about it.
That hunch hit, and the roots of giant trees in the courtyard were eroding the underground space.
Giant trees were rooting in rare mines and sucking away their magic.
Most of the rare ores, such as Demon Ore and Orihalcon, were just back in stone.