Before, in the memory dream thing, or whatever the hell that was, Karamatsu acted strangely when it came time to spy on his younger self. He swiftly averted any confrontation over why he wasn't as thrilled to do so.
It's not like he was trying to keep quiet over the possibility of it being his fault for them getting stuck in the memory world. None of them initially knew who's regrets it were that caused this, requiring them to look back at what happened for any of them to regret.
But he, like the rest of his brothers, did not want to reminisce about their days in high school. Regardless of how much they playfully picked on each other for their behavior at the time.
Having to remember the brief period of them avoiding each other and hardly talking wasn't fun.
Especially that fight they had on the day of graduation.
Ichimatsu hit the nail on the head when he concluded that's the reason Karamatsu took so long to speak up. The second born was hesitant to risk reminding them of that fight, but that went down a lot better and smoother than he'd expected. It was also helpful since it was that information that led them to finding the letter and Takahashi.
Which was nice. It was nice seeing his past self and strengthening the bond he has between his brothers.
The others actually listened to him, even going so far as to tell him not to apologize for reminding them of the fight. Even while going through all of the graduation albums with them and looking back with a smile of enjoyment rather than a frown of dissatisfaction, it was nice.
And yet he still feels something akin to guilt after all of that.
Not that he's telling anyone.
It wouldn't make sense to ruin the good mood that was established after breakfast.
What he doesn't know is that Osomatsu caught on to all of that somehow.
When Osomatsu had first asked Karamatsu what was wrong, he was most likely going to say it was probably his fault they were trapped in the memory.
But that didn't happen.
The eldest truly did want to ask again, but this and that happened. A.k.a, horse races. And then Iyami made them remember things.
But everything worked itself out in the end, right?
So why does Karamatsu still look like that?
As good as he appeared to be when they awoke from the dream, Osomatsu could tell something was on his mind.
The first born was unable to question Karamatsu properly with the graduation albums catching everyone's attention.
Osomatsu's suspicions only grew as Karamatsu suddenly left afterwards and didn't come back.
Normally, Osomatsu would leave him be.
But this seems to be following the same pattern as when they were in the memory. As much as Osomatsu tends to overlook things, he's attentive. Karamatsu is, in his own way, subtly telling Osomatsu something.
Not that Karamatsu is making his job any easier by not speaking up.
Guess I gotta talk to him since he obviously isn't going to say anything.
Deciding to find and confront the man, Osomatsu stood up and headed for the rooftop, that being the only place Karamatsu would stay at for a while without leaving home.
"Hey, Karamatsu! How long do you plan to stay out here?" Osomatsu exclaimed with a smile as he pulled himself up to the roof, instantly spotting his immediate younger brother.
Karamatsu turned to Osomatsu, quickly slipping a smile on, and responded, "Ah, I didn't intend to stay up here for so long."
He's speaking normally. Not sure if that's good or bad...
Settling down beside Karamatsu, Osomatsu said, "It's fine. Just wanted to check on you."
"Why?" Karamatsu asked, cocking his head slightly.
"You just kind of left without saying anything and didn't come back."
Karamatsu's face fell a bit as he said, "Sorry."
Osomatsu nudged him and said in a light tone, "Hey, don't apologize. It's not like you needed to tell us. Everyone needs their alone time, some more than others."
"...I was just thinking."
Taking a moment to construct what he's going to say, Osomatsu said, "I've been meaning to talk with you."
"About that dream. Or at least I think it's a dream. I don't remember as much as you, but I do remember you not wanting to tell us you were the one who had regrets."
Karamatsu looked down to his lap where his hands rested and answered, "Yeah."
Osomatsu continued, "I know we established that it was because you wanted to avoid bringing up the fight and all. But there's something else, isn't there?"
Not wanting to see whatever look Osomatsu was giving him, Karamatsu kept his gaze in the opposite direction and asked in a dismissive way, "What else would there be?"
Trying again, Osomatsu started, "From what Ichimatsu said, you didn't want to burden us with remembering it."
"But I know there's another reason." Osomatsu spoke in a prying but patient tone.
"...Not really." Silence passed as Karamatsu waited for Osomatsu to respond, only to feel a sudden pinch catch his attention. Karamatsu tended to his cheek as he turned his head in Osomatsu's direction and said, "Ow! What-"
Osomatsu fixated him with a serious look and cut Karamatsu off, "Karamatsu. What did I tell you about speaking your mind about things? If something's the matter, then just tell me."
Placing his hands back on his lap, Karamatsu answered in a low voice, "It's...stupid."
"It can't be that stupid if you're making a face like that." That only served to make Karamatsu return his gaze to his own lap. Osomatsu continued in a gentler tone, "Now c'mon, tell Nii-chan what's wrong."
With evident hesitation in his voice, Karamatsu asked, "...Do you...do you think, and be honest, that it was...right of me to bring up Takahashi's letter?"
"What do you mean? Of course it was right."
"I mean in the real world. Not in the memory."
"My statement still stands."
Karamatsu started, "But that..." He fell silent, not sure if he should finish his sentence.
"But what?" There was a hint of something in Osomatsu's voice, like he was beginning to piece together an answer of his own.
With his voice getting quieter with each word, Karamatsu answered, "Um... that's... how the fight... started..."
Not being able to see Karamatsu's face was a bit disadvantageous for him, but his words were more than enough to tell Osomatsu what was wrong. He asked, "Are you saying that it was your fault it started?"
So that's it.
"It's not just you. We're all at fault for it."
Karamatsu remained silent.
He pulled his knees up to his chest, hiding his face in the process.
Karamatsu curled in on himself even more, slightly digging his fingers into his sleeves and said, "...Of course it's my fault. Why wouldn't it be? I'm the one who forced you guys to come to the roof. None of you wanted to be there, obviously. Then I had to open my big mouth...and actually hit my own brothers-"
"Oi, Ichimatsu punched you first-"
"That doesn't matter." Karamatsu responded in a stern yet weak voice, "I shouldn't have done anything..."
Once Karamatsu fell silent, Osomatsu scooted over, simultaneously pulling Karamatsu closer, and said, "None of us blame you for any of that stuff. You know that, right?"
Karamatsu spoke quietly, "You should." The hand on his shoulder tightened as he said that. He continued, "It's not like anything different would've happened if I didn't call you guys to the roof. In fact, I regret putting you all through that. I'm sorry."
After waiting for Karamatsu to finish, Osomatsu spoke, "Karamatsu. You're an idiot."
Surprised by the unexpected (not too unexpected coming from Osomatsu) response, Karamatsu lifted his head to look at Osomatsu. "Eh?"
Osomatsu gave Karamatsu a displeased look and said, "I mean, we're all idiots. But you're really an idiot."
Blinking owlishly, Karamatsu asked, "Why?"
"Because none of us regrets that fight. So why should you?"
"Seriously, if it wasn't for that, then I don't know where we'd all be right now."
Relaxing his body a bit, Karamatsu asked, "Wait, why?"
Putting on a smile for the second time since the conversation started, Osomatsu said, "That's what made me realize we really couldn't keep ignoring each other like that. And I'm sure we all realized the way we were acting at the time wasn't good for any of us, either."
At the somewhat confused way Karamatsu looked at him, Osomatsu continued, "Basically, that fight knocked some sense into us."
Reaching to pat Karamatsu's head, Osomatsu said, "Yeah, it wasn't very pleasant to go through and think about. But it's behind us now. Besides, if we seriously blamed you for that, we would've said something."
Completely unfurling his body, Karamatsu spoke, "I guess...that makes sense. But at the time, we would've much rather not had gone through that."
"Yeah, yeah. But now we don't care."
"That's one way of putting it."
"Actually," Osomatsu's voice changed as he said, "we should be apologizing to you. We flat out ignored you went you were trying to reach out to us."
"No, there's no need."
"Is that so? Well then," Osomatsu grabbed Karamatsu's face, planting a kiss on his forehead, and said, "no more blaming yourself over this, okay?"
"Alright, you can let go." Karamatsu tried but failed to break out of Osomatsu's grasp as he felt heat rise to his face.
"I'm serious Karamachu-"
"What's with that nickname!?"
Osomatsu pulled Karamatsu into a hug, nuzzling his cheek into his hair, "Because you're my sweet little baby bro, that's why!"
Karamatsu simply retorted with, "We're the same age!"
That only made Osomatsu squeeze tighter and exclaim, "But I still love you!"
Karamatsu was powerless to the coddling, choosing to just hug back as he laughed along with Osomatsu.
After a moment, Osomatsu spoke up, "Karamatsu."
"It's not your fault."
Hiding his face in Osomatsu's shoulder, Karamatsu said, "...I know. It's kinda hard to accept that, though."
The sudden addition of another voice startled the two eldest sons, both turning to see Todomatsu halfway on the roof as he spoke.
"What's up?" Osomatsu asked as he prevented Karamatsu from pushing away.
Todomatsu smiled at the sight of Karamatsu in a flustered state and spoke, "Nothing. Just didn't know where you two were."
"Oh, we were just talking."
As much as Osomatsu just wanted to blurt it out, he didn't. He looked down at Karamatsu and asked, "Is it okay to tell him?"
Karamatsu looked up to Osomatsu, not bothering to turn and see whatever look Todomatsu was giving him (surely thinking Karamatsu doesn't look very cool at the moment). He answered as he glanced to the side, "If you want to tell him, then go ahead."
A few seconds of silence passed before Osomatsu replied to Todomatsu, "I'll tell you later."
"What? It's not like you need to tell him right now. It can wait.
Not wanting to argue at the moment, Karamatsu laid his head back on Osomatsu's shoulder and agreed, "...Alright."
Todomatsu spoke, "That's fine. See you inside."
Osomatsu replied, "See ya."
After Todomatsu finally left, Karamatsu relaxed a bit in Osomatsu's arms. Osomatsu asked playfully, "Is it really that embarrassing?"
"...You have no idea."
"But we treat them like this all the time."
"I don't get treated that way."
Osomatsu laughed and said, "Well I guess you should get used to it then, huh?"
"What does that mean?" Karamatsu asked with a raise of an eyebrow.
Flashing a mischievous grin, Osomatsu answered, "Exactly what it means, Karamachu~!"
As soon as Osomatsu said those words, he squeezed Karamatsu once again, rocking them both back and forth. Not even a second later, he began peppering Karamatsu's face with kisses.
Karamatsu was held prisoner as he protested, "Wai-! Aniki!"
"Alright, alright. I'll stop." Osomatsu said with a cackle, "Your face is so red."
"Who's fault is that?" Karamatsu retorted while hiding his smile behind a fist.
Standing up and holding a hand out for Karamatsu, Osomatsu answered, "Totally not mine."
Already missing the warmth from the hug, Karamatsu grabbed the hand in front of himself and said, "I guess it's time to go in now."
At the sight of Osomatsu and Karamatsu coming through the window, Choromatsu pried his eyes away from his light novel and asked, "You guys were gone for a while. What were you two doing up there?"
Before the two could answer, Todomatsu, who was in the room as well, said teasingly, "Osomatsu-niisan was babying Karamatsu-niisan again."
"Oi!" Karamatsu protested.
As Osomatsu closed the window behind himself, he took a moment to observe the scene playing out in front of him.
Choromatsu had long since put his book down to join Todomatsu in poking fun at Karamatsu. The poor guy was struggling to keep any redness from spreading on his cheeks, but it was quite obvious to Osomatsu that he didn't mind the attention very much.
It's nice that he's opening up more, but I really wish he wouldn't blame himself for everything.
I guess that's what I'm here for.
With that last thought, he joined the bandwagon and called, "Karamatsu~!"