While seated on a chair as his new 'mother' prepared for dinner, Hiroki slowly retrieved some memories about the host he had acquired and the life he was going to live from now on.
Apparently, this body's name was Hiroki Itou, just as Moriko earlier said. He was aged 18, supposed to be a high school student by now but due to an illness, he was ordered to stay at home and only met with a teacher twice or thrice a week.
Hiroki could barely understand these human terms at all. What he only understood was this fact―other people weren't too happy with his strange illness. They treated it as some kind of curse.
Anyway, he had to see through the host's background and assess its present condition to purify this curse, whatever it was.
First, his childhood - Hiroki Itou's father left as soon as he was born and his mother died a few years later on. Orphaned at a young age, Hiroki Itou was taken in by his maternal grandmother in the countryside. Because his mind and body didn't grow the normal way, he spent most of his childhood and teenage years doing nothing but helping his grandmother with house chores and sneaking out and getting lost in nearby forests that ended up being a full on search operation that made his grandmother nearly experience heart attacks.
At this time, Hiroki Itou had seldom spoken and he also didn't know how to read or write. Suprisingly, however, he knew how to count.
It was only when his grandmother died that he was again taken by another family - one of his mother's siblings with a family her own, in the city proper. Although that family's house seemed to have a wider backyard and spacious rooms, Hiroki Itou still felt it was empty. This was for the reason that the father rarely came home and the sons and daughters almost never spoke to each other unless they would order Hiroki to do something. A few years after he was adopted to this family, social workers appeared on the doorstep and Hiroki Itou, age 17 then, was once again taken away.
It was then he was brought to this third family ― the family where Moriko and her daughters currently lived together somewhere in between the countryside and the city.
In this place, houses were interesingly categorized into three: rich, middle, and poor.
Based on his assessment, Hiroki Itou's first family on the countryside could be regarded as poor, the second family was rich, while the third and present family with Moriko was in the middle.
Like the worlds he had traveled to before, each family consists of members such as, a mother, a father, and their children. But for some reason, the Itou family was missing a member.
Hiroki was silent as his eyes went over to Moriko, observing her movements. The way she cooked faintly reminded Hiroki of those chieftains' wives whenever he helped a village and made him eat food they prepared as a thanks for helping or saving them from monsters.
Although, this time, Moriko wasn't giving him food as a thanks. Hiroki wondered what it truly was for deep inside. After all, Hiroki hadn't done anything for her yet to do such a thing... It wasn't like he just completed a mission either...
Thinking about missions, Hiroki suddenly remembered an important thing.
"...Mom," he called Moriko faintly. It still felt strange to speak this word but Hiroki knew he had to get used to it. Especially now that he found a new mission―to retrieve a cure for this host's illness and improve his overall health.
Moriko's head rose, her hands promptly stopping from cutting a vegetable as she turned to Hiroki. "Hmm? What is it? Do you want something?"
Hiroki's face was serious as he said, "... the Math exam. I want to take it."
Math examination. When Hiroki first heard it, he thought it was some kind of poison or weapon. But as it turned out, it was a subject in this world that people, his age especially, needed to learn so they could improve their intelligence. At least, that was what the book on his table stated earlier when he tried reading it. Thankfully, there wasn't any language barrier as he had previously expected. It made everything much easier.
Only, he had to do something about his health. He was too weak he felt this body wouldn't even survive in harsher places like the desert or a snow mountain. There was also the fact that he was regarded as someone with a mental condition.
Hiroki Itou's memory helped him recall what exactly transpired before he took over his body. Apparently, that math exam was the last thread of hope for Hiroki Itou to prove his intelligence wasn't too low to the point of being useless. Since Math was the only thing he was good at, the teacher who came by made Hiroki try memorizing and solving slightly more advanced equations and problems. She said it was to test Hiroki's intelligence about Math and if luck was on their side, Hiroki could use it to request more tests on other subjects and could use them in school admissions if he ever gained favorable results from the tests.
Hiroki actually did great in this Math exam, but for some unknown reason, unfortunately, he didn't finish it.
"Eh... Y-You want to take another math test?" Moriko was slightly surprised, remembering Hiroki who suddenly stood up and left while halfway finishing the said test. He refused to speak to anyone after that, as if having a tantrum but in the form of painfully dead silence that left people in confusion and worry.
"Hiro-kun, how about trying the test next year? You can focus on studying a bit first and doing some other things..." Moriko suggested with a smile. Obviously, she didn't want to put pressure on Hiroki. This child had even barely stayed in their house for a week. He was still new to the environment, never mind being comfortable to everyone in this house.
Even with the teachers and other professionals suggesting to try other advanced tests, Moriko was worried about Hiroki. She was afraid Hiroki would only hate studying even more once pressured and forced further.
Silent as she pondered on her son's situation, Moriko couldn't help but sigh. Hiroki's teacher said that it would be too difficult for Hiroki to study in the same age group as he was already too far behind. Even the Math test was just a chance of luck but that too he couldn't finish right now, so how could they force him to enter a more advanced educational institution?
Wasn't that just forcing a child to be ready when he wasn't still ready?
But Hiroki, this retired hero, wasn't the type to stop and back down easily. Things such as 'ready or not ready' were not real options for him.
He took challenges like he devoured special attributes and mana from dragons. He had slayed countless of ferocious beasts while traveling alone. He had done and passed thousands and thousands of tests and trials in quests before.
Math. It was a series of numbers mixed with letters and seemingly ancient symbols that looked like those desert ruins he had seen before. If his memories served him right, those kinds of symbols could be learned and controlled, and finally absorbed to one's system to be put into good use.
Similarly, Math could also be like those magical ruins.
Just like any another opponent Hiroki had encountered before, this thing would have to have weaknesses too and once he figured them out, he could use them to tame it and absorb it to form into his own energy and power.
"... I want to take it, mom," Hiroki said again, this time more determined and decided. He faced Moriko and told her directly, "...Let me take Math exam again."
Having a weak body wasn't enough of an excuse anymore. As he had seen from his discoveries about this world, a human's lifespan could only reach a certain point until it finally ended and nothing would come after. Before that point flashed by and disappeared into nothingness, Hiroki had to gather strength and improve this host's life. At the very least, that was what he could do as a 'son' to his mother, and as a retired hero whose wish was respected and granted by God.
But in order for that to happen, first, he would have to tame this beast called Math, then proceed to the next test to level up and then finally, cure his curse.
Who said Math couldn't be tamed, anyway?