"I went on another mission today… but still haven't found the demon with the iron fan—the one who took Kanae's life."
"I take on more missions than any other Hashira. I thought I could avenge her faster that way, but he hides too well."
"Today I saw another man-eating demon. They never change—always lying, always craving flesh."
---
"Wednesday — Weather: Cloudy."
"Kanae, I miss you."
"You know, sometimes people are scarier than demons. I've saved so many, only for some to curse me… even wish to become demons themselves."
"I wanted to kill them. But I can't—I'm a Demon Slayer. We save humans, no matter how twisted they are."
---
"Friday — Weather: Rain."
"Kanae, I met a demon who lives peacefully with humans today. I used to think your compassion for them was foolish… but maybe you were right."
"Her name is Nezuko—sweet, gentle, and strong. Just like Kanao. I told her brother that I'd entrust your dream to them."
"But I met someone else too…"
The page ended there.
Lock's eyes lingered on the last line. Judging from the timing, this must have been written right around when he'd first arrived in this world.
Curiosity stirring, he turned the page.
"I met someone interesting today."
"His name is Lock. Kanae, do you know what's strange? He's only about Muichiro's age, but his talent… It's unlike anything I've seen."
"I practically stole him away from the Master's meeting! Every Hashira wanted him—but, well, I was quicker."
"Still, he has some kind of conflict with Sanemi. The two nearly fought in front of everyone!"
---
"Monday — Weather: Sunny."
"Kanae, you'd like Lock. He's strong, stubborn, and has a sharp tongue. And… he actually teases me now."
"Even Kanao seems to smile more when he's around. I didn't think anyone could reach her like that."
"Tonight, I went to check on his training. His progress is incredible."
"I wanted to tease him—but he caught me off guard. He got way too close."
"Doesn't he know he shouldn't do that with girls unless he likes them?"
"Kanae, I even shared my breathing technique with him. If I could, I'd almost want to take him on as a pupil… or maybe something more."
"Do you think Lock will ever leave the Butterfly Mansion? I'm not sure why, but I've grown fond of him."
---
"Tuesday — Weather: From sunny to cloudy."
"Kanae, I think Lock might be in trouble. He's young, but somehow manages to drive me crazy."
"He reminds me of you sometimes—his smile, his sword, even the way he never gives up."
---
"Wednesday — Weather: From cloudy to clear."
"I met with the Master today. He praised Lock's progress, and… I felt proud."
"I've always thought of him as someone I needed to protect, and hearing the Master's words made me happy."
"I saw Lock again tonight, Kanae—you wouldn't believe it! He created a new breathing style!"
"He called it Bee Breathing. Said it was a variation of my Insect Breathing. I guess that means my technique was inspiring after all."
"I'm planning to send word to the Master through a crow—Lock deserves recognition for this."
Lock couldn't help smiling faintly as he closed that page.
So that's what she thought of me…
Always calling him "kid," always teasing—but in her own quiet way, she'd looked out for him since the beginning.
His smile faded as he turned to the last entry.
"Another mission today. The crow reported a demon sighting on Mount Akitake. Supposedly a lower rank."
"Giyu isn't available this time, so I'll lead the squad myself. Kanae, wish me luck."
Lock snapped the notebook shut.
His gaze hardened.
A lower-rank demon?
Something didn't feel right.
It had been five days since Shinobu left. If it really were a mere lower-rank demon, she should've returned long ago.
Unless—
No… it can't be an Upper Rank.
But his instincts wouldn't quiet. The thought alone made his chest tighten.
In the time he'd lived here, the Butterfly Mansion had become home. And Shinobu—
He couldn't bear the idea of something happening to her.
"Lock? Are you down there?"
Aoi's voice echoed faintly from above, followed by hurried footsteps.
She reached the basement door, peering inside. "That's strange… I could've sworn he was here."
At that same moment—
In another room, Kanao froze mid-step.
When she turned, Lock was standing there. His presence was silent, yet determined.
"Lock?" she said softly, clutching her broom.
He gave her a small smile. "Kanao, can I borrow your Nichirin Sword?"
Her eyes widened. "My sword?"
"I need to train tonight. I'll return it tomorrow."
He reached forward lightly, his fingertips brushing against hers. The contact made her breath hitch, color flooding her cheeks.
"…Okay," she murmured, handing the blade to him carefully.
As she did, her hand lingered—gripping his for a moment. Her eyes met his, full of quiet worry.
"Be careful," she whispered.
Lock blinked, surprised by the rare emotion in her voice.
He nodded once. "I will."
Before leaving, he gently pulled her into a brief embrace.
Kanao froze, eyes wide, her face burning red as he leaned close enough to murmur, "Wait for me to come back."
Her hands trembled. "O-okay…"
When he stepped back, she reached out as if to hold him—but he was already gone.
All she could do was clutch the hilt of her empty scabbard, the warmth of his presence still lingering in the air.