Apparently, there was an anomaly in the mana required by the grail for its manifestation— due to which the grail was manifested sooner than it was suppose to be. Though the servants were yet to be summoned, grail had started choosing masters for their participation in the Holy Grail battle.
Rin was on of them— perhaps the first person to receive Command Seals. The remaining masters were still a mystery.
"Why are telling me all of these?" Shirou asked, standing while cleaning dusts off his shoulders. "I don't think it concerns me anymore since I'm not chosen this time around."
"Perhaps not." Rin replied, "But you're still a mage who fought during the previous one. Whether command seals appear or not, you still have a lots of mana. It may draw unwanted attentions if other masters were to find out about you…"
"So what?"
"Jeez! Let me finish already, will ya?" Rin shouted, making a balloon face, "I was saying that before someone else notices you, join my forces. Together, we can summon a powerful servant to win the war."
"Basically you want to use the mana within me, don't you?" Shirou said, checking the boxes that was layered with dust on the corners.
"It's not like that. I just…I just want to save you…"
"From what, Tohsaka?"
Rin lowered her eyes as though regretting her past actions. It wasn't easy for her to come and ask him— not in the slightest.
A lots had happened, and they both changed for the greater good.
Taking his current strength into consideration, she knew Shirou won't be any trouble. But keeping him by her side was a much safer option than letting him run into other servants like last time. He was nearly killed that time.
"I don't want you to get hurt like before." She continued with a gentle voice, "If something happens to you, I won't be able to keep his promise to look over you?"
Shirou halted.
Sometime memories are bitter and people tends to avoid them. But when those memories are parting words from the close ones, they can no longer be avoided.
Indeed, Shirou had some too. That was the reason why he was attempting to forge Artoria's Noble Phantasm.
It was same for Rin as well. Archer asked her to look over Shirou that he may not end up being in misery again. Yet, when Rin and Shirou parted way— it wasn't a happy one, rather filled with arguments and ego.
Rin, by the way, was able to overcome her ego. Sure it took her long, but she did at least.
"You know what?" Shirou replied, his voice clam and low, "Maybe it's because of me that you have to engage in another Holy Grail War."
"Wh—" Rin was taken aback by him as her bewilderment rose up, "What're you saying? It isn't your fault that I was chosen. i…"
"I didn't said it either." He interjected, "What I meant is this war. Perhaps, I'm the reason why the grail started manifesting. You did tell about the anomaly."
Rin was still confused until Shirou emptied a few boxes before her. From the boxes, started falling tons of artefacts, mana crystals, gems and so many other things. And each one of them didn't had a hint of mana in them.
"You were eager to know what I was doing right." Shirou looked at Rin, his eyes showing remorse, "I was doing madness."
"I don't understand." Rin stammered, her eyes shaking, "What's this all about, Emiya?"
"I was desperate." Replied Shirou, "I was desperate to see her once more. And it leads me to several methods which might help me achieving my desire."
He took a deep breath before continuing again.
"I thought performing a summoning ritual with enough mana preserve would help me to summon her. Since I already had her scabbard implanted within me, I could've summoned specifically her without any additional relic, just like the last time."
He took another breath.
"But my carelessness led me to use more mana than necessary and it disturbed the mana balance, leading as far as to from a grail itself. And I wasn't even chosen to be a master."
Rin couldn't believe what she was hearing. They were all new to her— an entire different perspective than what she had anticipated. But they weren't fabrication.
Shirou's attempts to summon Artoria could be the cause of what he described— specially when he had used excess mana.
But she couldn't blame him.
Shirou's relation with Artoria was more than just master-servant pact. They were adored by each other. They loved each other.
Having his loved one separated without saying good bye to her, lead him to feel distress. He was sad, lonely.
And Rin— she understood that quite well.
"If I were at your shoes, I would've done the same." She replied, "But I'm mad. You never bothered to tell me what was going on and just kept that to yourself."
She approached him, too close in fact. Now her mad face was just before his.
He smiled as to avoid her, but his impression were still the same— gentle yet lonely.
"As for the result, you'll have to come with me." She insisted.
Shirou wasn't brave enough to decline her. But he changed a little and turned her proposal anyway.
"I'm sorry, Tohsaka. But I really can't." he smiled, "there's something that only I need to take care of. Until then I can't help you."
"Is that so… E..MI..YA." she leaned towards him, almost her chest touching his, "Then if you take care of those things you'll accept."
"Maybe so..?"
"Then I suppose I have no choice but to help you in your matters…"
"You don't have to." Shirou almost shouted, but soon regain his composure, "Like I said before. Only I can take care of. And I promise, after that, I'll be all yours."
The last part made her blushing. And she stepped back. She did nothing but a nod. And then, perhaps out of embarrassment, she came out of the storage shed, and started running again.
Shirou stood there confusedly, watching her off until she turned right from his house entrance. He smiled gently and murmured.
"Sorry, Tohsaka. But I need to do it."