My Cute Wife is Mitsuri Kanroji

"Here it is." 

Finding the hole just beneath the nape of the robot, Kotaro inserted the key and rotated it. Even though it's a type of robot, in reality, it's more of a doll. The key has to be rotated to give it power to move. 

Once. Twice. Thrice. 

Kotaro rotated the key as best as he could, and then… 

Kr…! 

With a slightly rusty sound, the robot stretched its arms, all ready to act as a battle robot for Kotaro. 

"Alright. It's time for training." 

Kotaro held his wooden three-section staff, fully prepared to face it. 

… 

Bam! 

Swoosh! 

The sounds of clashes kept reaching his ears, snapping Kotetsu back to his senses. At first, he was a bit confused, then remembered the key. 

"Where is the key?! Don't tell me… That man took it!" 

He quickly turned around and saw the sparring match between the robot and Kotaro. 

Kotaro was able to face the robot wielding six blades at once with nothing but a wooden three-section staff, though he was at a disadvantage. 

Whoosh! 

A sword strike came from above, and when Kotaro went to block it, another one came from the side, accompanying the strike from above. The wide range of attacks coming one after another, from different angles with just a slight time lag, tested Kotaro's reflexes. 

How good was he at reading attacks? 

How could he fend off those strikes? 

Should he block or dodge them? 

The battle with Yoriichi Type Zero wasn't about pure strength but rather skill. And, to his fortune, this was exactly what Kotaro needed. 

Moreover… 

"Since it's a robot, I don't sense any intent." 

The thing Kotaro was facing was artificial, so there was no intent like the Killing Intent from Kamanue or the Fighting Intent from Mitsuri, making it a bit tougher for him. 

Swoosh! 

A blade aimed at his legs, forcing Kotaro to take a step backward. But the robot seemed to predict this and took a step forward, making the blade fall toward Kotaro from above. 

"Tsk! Is this really a robot?!" 

If Kotaro's staff had been a genuine Nichirin three-section staff, blocking this downward slash wouldn't have taken much effort. 

But he was wielding a wooden one. With a wooden weapon, he was facing a metal one. 

With no other option, Kotaro grabbed the second and third sections of his three-section staff, pulled them tight so the chain joining the sections was taut, and positioned the chain in front of the oncoming blade. 

Ting! 

Since wood couldn't block metal, he used the metal chain to intercept it! 

But even the chain couldn't fully stop the strike, so rather than attempting to block it entirely, Kotaro used the momentum of the strike to deflect it. 

Now, with the blades lowered, he had a chance! So… 

Bam! 

He spun and smashed his staff directly against the face of Yoriichi Type Zero, sending it flying to crash into a tree! 

"Oops! I put a bit too much strength into that." 

Now, he hoped the kid was still unconscious, sparing him any future trouble. But… 

"NOOOO!!" 

Kotetsu, witnessing the disaster with his own eyes, cried out and ran toward the robot, which had stopped moving after the heavy impact. 

Though not an expert, he started touching the robot all over, trying to examine it. 

Sigh… 

Now, Kotaro was feeling bad for him. He did take the key without consent, and to make matters worse, he had smashed the robot, leaving it paralyzed. 

"Y-You…" 

Kotetsu turned toward Kotaro, trembling in rage as he pointed a finger at him. 

Kotaro now felt maybe he should apologize to the kid. Though he might not accept it, still… 

"W-Well, I am sorry. But look, it's still fine!" 

Kotaro grabbed the Yoriichi Type Zero and shook it a bit, trying to show Kotetsu that though he'd struck it a bit hard, it was alright. 

But as soon as he shook it… 

Crack! 

A crack appeared on the face, and a piece fell off. 

"…" 

"…" 

Never in his life had Kotaro felt a kid's gaze could make him sweat. 

"Haha! Look, despite being damaged, it can still move. Isn't that amazing?" 

"..." 

It was decided. Kotaro resolved to stay cautious even in his sleep. Who knew when someone might try to assassinate him. 

… 

"I did apologize. Why are you making such a fuss?" 

"Shut up! Shut up! You broke that doll!" 

Kotetsu just cried more and more over that broken piece of the robot. Even though Kotaro could understand the sentiment behind it, he still felt it was a bit too much. 

"Then, if you repair it, won't that be alright?" 

"What do you know! That doll… That doll was made by my ancestors. The technology used to make it is very advanced, and we don't know the way to replicate it. If it is broken, we can't repair it!" 

Listening to all of Kotetsu's words, Kotaro just had two words in his reply. 

"So what?" 

Kotetsu thought that maybe this man could understand his worries and stop damaging the robot any further. But after hearing such cold words in return, his anger spiked even more. 

"Y-You…" 

But Kotaro didn't say it out of spite or coldness. He meant it in a more meaningful way, as advice to the kid. 

"You said your ancestors made this doll, right?" 

"That's right." 

"Then… For what purpose did they make this doll? Was it to keep it as a heirloom, just like you keep it?" 

Kotaro's words struck an uncomfortable chord in Kotetsu's heart. Yoriichi Type Zero was made as a battle robot, used for training Demon Slayers. 

"What if it's broken? It's broken fulfilling its purpose. Or do you think that if you keep it as it is, it won't break for eternity?" 

Even if the robot were preserved as it is, someday its lifespan would run out. Nothing is eternal in this world. 

"Rather than keeping it as a heirloom, it's better to use it for the purpose it was made for. And you, rather than saying it can't be repaired, should learn how to do it. Or else, even if not by your hands, someone else will break this doll." 

With those words, Kotaro left the place, leaving both Kotetsu, who looked down with clenched fists, and the silent, slightly broken Yoriichi Type Zero. 

A few steps away, Kotaro stopped and turned to look at the kid before moving again. 

"Maybe, I was a bit too harsh. But… It's the truth." 

And he believed his words would inspire the kid to study that robot. After all, motivation fueled by anger is powerful. This was his way of compensating the kid for breaking the robot.