Yi Bang-won was a father who loved his children more than anyone else.
So even when his eldest son, Prince Yangnyeong, was always getting into all sorts of antics, he protected and defended him to the very end.
Because Yi Bang-won cared so deeply for his children, he never took what Kim Daebung said lightly.
"Royal physician Kim Ho-il must answer every question I ask without a single lie."
"Yes, Your Majesty."
Kim Ho-il, the chief physician of Naeuiwon and the finest of the royal physicians, trembled all over at Yi Bang-won's words.
No, if there were anyone who didn't feel fear in this situation, that would be stranger.
Yi Bang-won was wearing a black dragon robe, and a low table in front of him held an iron mace.
"Tell me in detail what His Majesty's current health condition is."
"His Majesty is a bit overweight, but there is no major difficulty in getting around. He works a great deal, but he gets at least the minimum amount of sleep and eats enough... his condition is only something that needs a little careful watching; it is not the sort of state that would worry Your Majesty the Grand King."
"Hmm, so it is indeed."
After hearing that much, Yi Bang-won immediately reached for the iron mace.
The sight made cold sweat pour down Kim Ho-il's entire body like rain.
He felt as though his head might be smashed open at any moment.
"If you answer honestly, I will bestow great rewards on you and ask no questions about any crime. But if you tell even the slightest lie, I will charge you with the crime of deceiving your sovereign and punish you severely."
"Yes, Your Majesty the Grand King."
"I will ask again. What is His Majesty's health condition?"
"As a royal physician, I could not bring myself to report something uncertain, but... His Majesty's royal body is not in very good health."
"Be specific."
Kim Ho-il took a breath and spoke carefully.
"His Majesty likes fatty meat and eats a great deal of royal food. Because of that, a great deal of fat has already built up in his body, and if this is left alone for a long time, there is a high chance that a serious illness such as sogal will appear."
"Sogal, huh."
"Yes, that is correct. However, being overweight does not mean sogal will definitely appear, so it only raises the probability of it developing. This humble servant could not say it with confidence."
Being a royal physician was a job you did with your life on the line.
Of course, in Joseon they did not kill a royal physician just because the king had fallen ill with a serious disease that was hard to treat and the physician couldn't cure it.
At most, they would punish him by sending him into exile for a while under the pretext of punishment, an exile almost like a trip.
But if a royal physician's misdiagnosis caused the king to die, he could be executed, and in the worst case he could even be put to death for treason.
And if the king or a royal family member wasn't even seriously ill but he said in advance that they might become sick, his head and body could be separated for the crime of speaking carelessly.
"Please kill me, Your Majesty the Grand King."
Yi Bang-won was angry at the royal physician for not reporting it properly to him and to Sejong, even though he had foreseen this situation to some extent. But he could also understand the physician's position.
So he decided to show mercy.
"...... Your crime deserves death, but I shall specially grant you a chance to atone by earning merit. What should I have you do?"
"His Majesty is a little too burdened by fat buildup, but he is still young. So until his body returns to normal, merely cutting his meals a bit and moving around a great deal will be enough."
"What about hunting and the like?"
"Hunting involves riding a horse, using the lower body a great deal, and moving the whole body, so it would be excellent exercise for His Majesty, whose body has quite a bit of fat buildup."
A smile spread across Yi Bang-won's face.
Until now, he had to argue with a rather vague line of reasoning—that he was worried about the king becoming obese—so he hadn't been able to go hunting very often...
Now that the finances were flush, too.
If he framed it as a national project that had to be done for the king's safety... wouldn't once every two weeks be possible?
"What do you think about His Majesty staying up late every night to review memorials?"
"The intention behind staying awake until late at night and personally handling everything is admirable, but as a physician I do not think that is very good for His Majesty's health. A person needs at least 3 si-jin (6 hours) to 3 si-jin and a half (7 hours) of sleep a day to maintain health, but His Majesty does not even sleep 2 si-jin and a half (5 hours) a day, so his body will be strained."
Sejong, like Yi Bang-won, was very fond of women.
In other words, five hours a day would be the official sleep time on paper, and his actual sleep time would probably be only around three hours a day.
"As a father, I shouldn't just stand by and watch my child overwork himself until his body breaks down. I seem to have been too careless. I must set this right."
Yi Bang-won was pleased.
Now he had a legitimate reason to take even his grandsons hunting once every two weeks while taking care of his son's health.
As he was getting older and no longer what he used to be, his body already felt stiff, and yet he could use Sejong as an excuse to do all kinds of exercise every day...
What a wonderful thing this was.
'As expected, Kim Daebung is a loyal retainer for the ages.'
The other ministers knew Sejong's health was likely poor, but they couldn't report it for fear of having their heads flattened by the iron mace; he had reported it this way and prevented trouble down the road.
There was no retainer like this in the world.
"This happens to be the time when the officials are leaving duty."
Yi Bang-won immediately went to where Sejong was working.
His face was full of smiles.
**
At Sajeongjeon, Sejong, who was working late again today to establish policies for the people, was visited by an unexpected guest.
"Your Majesty."
"No, Father, what brings you to see me at this hour?"
"I came looking to climb Bukaksan with Your Majesty."
At the mention of Bukaksan, Sejong flinched for a moment.
Just thinking about all the hardship he would have to go through climbing the mountain was absolutely dreadful.
His father Yi Bang-won might climb all the way to Bukaksan's summit while laughing heartily, but with his bulky frame, he would have to suffer terribly.
So Sejong turned as white as a sheet, like the future Hwang Hui, who once again couldn't resign.
However, he had his own all-purpose shield...
"Your son needs to spread the Bangwon Law more widely and distribute the periodic markets as quickly as possible. I am very busy because I have to devise policies for the people."
If this had been the old Yi Bang-won, he would have turned back saying there was nothing he could do after hearing that.
But now things were different.
He had the life-risking blunt remonstrance of Kim Daebung, the future loyal retainer for the ages, and even the royal physician's assurance that he was right.
"Your Majesty, Kim Daebung, who returned to Hanyang yesterday, remonstrated with me. He said that His Majesty's body had become quite overweight, and that if things continued like this, he could one day fall ill with sogal and seriously damage his body. So I checked with Royal Physician Kim Ho-il, and he said there was not a single thing wrong with what he said."
If Yi Bang-won had established royal authority with the iron mace, Sejong defended the royal authority Yi Bang-won had established through debates grounded in his immense knowledge.
Thus, true to being Joseon's greatest intellectual, he tried to get past the ordeal of mountain climbing by presenting proper grounds, but...
Sejong could not find any grounds to oppose his father's words.
'No, this can't be. I like sitting down, reading books, and working.'
While Sejong was flustered, Yi Bang-won began to pull out the strongest trump card in the Confucian worldview.
"If sogal develops, not only will fatigue build up in the body, but eventually a brain tumor can form, and you can even go blind."
If a mere royal physician had said this, Sejong would have compromised by cutting back on meat dishes for a few days.
But Joseon was a country that put filial piety above everything, where if a child took the cudgel blows for a guilty parent, the whole village would rush to praise it as filial devotion.
Thus Sejong could no longer resist Yi Bang-won, who was pressing him with sound reasoning and filial piety as weapons.
Yi Bang-won, armed with righteous logic, was Sejong's natural enemy.
"In the worst case, you could even die young."
If anyone else had said that, the moment they brought up the possibility of the king dying, it would have been treated as treason, and people would have immediately called for his entire clan to be exterminated.
But since the speaker was Yi Bang-won, the message had no choice but to be interpreted differently.
"I do not wish to suffer the tragedy of losing a child. So from now on I will steel my heart, make His Majesty move his body briskly, and also make him eat a balanced diet. This is because it is something I must do as a father to protect my child."
Sejong was moved by Yi Bang-won's paternal concern, yet he also felt his vision turn white.
Because from now on, he would have to be dragged around by Yi Bang-won, who was armed with perfect justification, and made to exercise intensely.
"From now on, His Majesty will climb Bukaksan with me every day, at the time when the officials leave duty, and build up his lower-body strength."
"Bukaksan?"
"...... Isn't that only natural? Even I, now that I have reached the age of fifty, can easily climb Bukaksan. And now that tax revenue has become plentiful and we no longer have to worry about the budget, let's go hunting once every two weeks and train His Majesty's royal body."
As soon as he finished speaking, the palace maids and eunuchs serving Sejong brought clothes for him to change into.
That was possible because they had already agreed with Yi Bang-won's words.
Everything proceeded without a hitch, and Yi Bang-won took only a small escort and climbed Bukaksan with Sejong.
"...... Doya! It has only been 2 gak (30 minutes) since we started climbing, and you're already tired? Hurry up!"
Sejong was truly walking with all the strength he had left. Breathing was difficult, and his whole body was soaked with sweat.
He wanted to sit down or lie on the ground at once.
'I want to go back to the palace and review memorials.'
'I want to go home...'
But Yi Bang-won, whose hobby was hunting, was walking as if nothing were wrong.
"My knees hurt so much that I can hardly walk..."
At those words, the royal physician rushed out. Royal Physician Kim Hong-il examined Sejong's knees this way and that, then nodded.
It was a sign that there was no problem.
That day, Sejong finished climbing Bukaksan in 1 si-jin (2 hours). Half of that time had to be spent resting rather than walking.
Naturally, he hadn't been able to get anywhere near the summit, and had only made it as far as around the middle of the mountain.
"...... Father, please spare me..."
"Doya, it is good to devote yourself to the memorials, but your body has to be healthy if you are to care for the people better. So tomorrow and the day after, you will climb the mountain and move your body. Understand that."
The next day, Sejong was tormented by full-body muscle aches.
But his suffering body grew steadily stronger.