Turns out all it took to get better treatment was to lean into the divine narrative that was going on. The Kisiragi line in this world was seen as divine and he used that to its full effect.
After all, a child of only a year old was able to read and write and even offered deep insight into things was nothing more than divine insight.
That was the only way to get people to listen to him, so as soon as he was able to speak words, he immediately went all out. Now even his father listened to his words or at least took them into consideration.
His reforms were simple, as soon as he was weaned, he ordered cow or goat milk to be boiled and fed to babies instead.
In this world where water borne diseases were more common, it wasn't really a surprise that child mortality was very high, wet nurse feeds and it's only God's grace that babies don't get any of the diseases.
He started inoculation early using himself as the test subject… This is something he didn't expect would have been so life threatening but thankfully he survived.
At age 2, he was granted almost 3 hectares of land by his father because of the inoculation treatment, he had used that to plant legumes and tubers and other crops… Which he sold for cheap so that other farmers could plant them to.
Turns out this put an end to an ongoing famine… He wouldn't know, he was one of the daimyō's precious sons,
He forced the boiling of water before use by providing communal tanks… Large tanks were placed in several locations and coal was used to boil the water three times a day.. Rudimentary tap designs allowed villagers to fetch water from it.
The hand pumps were also invented as well. He had even created a festival to force the adoption of these other plants.. A festival of new dishes where commoners could earn some money if they presented a good dish.
He taught how to make clay bricks and that cemented his title as Inochi-dono aka the Lord of Life.
In simple terms, he had completely changed this era simply because it was his instinct as a system administrator to systematize cures. He made these solutions a better alternative than not adopting them.
He didn't want to die from waterborne diseases so boiled water was introduced and systematized.
He was tired of rice so he planted other crops and forced its adoption through the festival of new dishes that has been renamed into the Inochi festival.
He nearly suffocated once when the wet nurse swaddled him a bit tighter than should be so he found and bred sheep to harvest their wool for clothing for babies and young children
His first winter nearly killed him so he taught clay brick baking and laying to the best of his ability and now his home even in Konoha was made from bricks.
Things he had solved as a means of surviving rippled outwards and now, he couldn't separate himself from the title of Inochi even if he tried.
However after about 5 years of striving for survival, his father had chosen to organize the Inochi festival of that year which made it a national event.
A theater group was invited to perform and in front of him, Saburo had seen the actors transform and use techniques that no matter how he tried to rationalize it, made no sense.
It was then that he found out how magical this world truly was, Hayato the guard assigned to him since he was 4 turned out to be a samurai.
In this world, it wasn't a status, it was a discipline that rivaled the shinobi, of course there were many others like the Onmyōji and the Miko.
The world may not call it mana or magic like the fantasy stories he was more familiar with but he was dead set on learning more about it.