Before I knew it, I was standing in a familiar flower field. Or rather, I was deep within the Sanctuary... It was an incredibly abrupt summons, but having experienced this so many times, I was used to it. Instead of surprise, my first thought was, "Ah, Shiro-san again."
Even though I was accustomed to the scenery suddenly shifting, that didn't mean I was currently at peace. In fact, I was in such a tense state of mind that I felt like I might break out in a cold sweat.
The reason was simple: whenever she summoned me like this, her requests tended to be reckless or completely out of left field.
"...Well, hello for now, Shiro-san."
"Welcome, Kaito-san. It is good of you to come."
"I didn't really have a choice in 'coming,' but... anyway, what is it this time?"
I thought it was a bit rich for her to say it was good of me to come after she had summoned me by force, but I could let that slide—it was Shiro-san, after all.
What concerned me was Shiro-san's current state. I pride myself on being more sensitive to her emotional nuances than anyone else in the world—self-proclaimed though it may be—and by my estimation, she was in a good mood. No, she was actually in very high spirits.
At the very least, it didn't seem like she had summoned me because of some grievance or because she was sulking.
"To think you know me better than anyone else in the world, or rather, that you know everything about me... Fufu, as expected of my lover. You certainly have some audacious thoughts."
"No, I wasn't saying... or even thinking quite that much... well, as long as you seem to be having fun, that's what matters."
I didn't quite understand why, but Shiro-san was in high spirits. In terms of danger signals, this was about a yellow light. While she might just be happy, there was a high probability that she was about to make a bizarre proposal.
"Now then, to the main point... Kaito-san, come walk around the Hydra Kingdom Founding Anniversary Festival with me."
"...Eh? N-No, wait... I've already promised Alice I would go with her."
I asked back, somewhat bewildered by her confident declaration. Setting aside the massive uproar Shiro-san's appearance at the festival would cause, the most important issue was that I already had a date with Alice.
Shiro-san was usually considerate about such things. She wouldn't try to forcibly change a plan that was already set.
If she was inviting me, did that mean she wanted the three of us to go together? I doubted it. If that happened, Alice would likely be miserable. For all her quirks, Alice was a relatively sensible person; if the three of us went together, she would probably spend the whole time managing Shiro-san.
And as for Shiro-san herself, I didn't think she would want that either. If I had been going with Kuro, there was a chance she would have complained that only Kuro was being unfair, but with Alice, that pattern didn't fit.
That was why I was so confused, yet Shiro-san spoke to me as if the solution were perfectly obvious.
"Yes, I have no intention of interfering with your date with Alice. I will be satisfied with the 'Second Day of the Founding Anniversary Festival'."
"...What... are you talking about?"
Wait, now she was saying something even stranger. Depending on the context, this was the kind of thing that could destroy the stomachs of several people at once. The Second Day of the Founding Anniversary Festival? No, no... If Shiro-san forced the issue, it would certainly happen, but that would be far too reckless.
Shiro-san smiled, seemingly having anticipated my reaction.
"There is no problem. I do not mean that the Founding Anniversary Festival will be held over two days."
"...Then, what do you mean?"
"Kaito-san, you are familiar with the concept of a Parallel World. This is an application of that... Essentially, for this Founding Anniversary Festival, I will create a timeline where you went with Alice and a timeline where you went with me. By having only your consciousness continuously shared between the two, the festival remains a single-day event in the eyes of the world, yet you will be able to experience both versions of it."
"............"
This God just did something absolutely outrageous. She was using her Almighty Power to its fullest. In other words, while the world only experiences one day, after I finish my date with Alice, I'll experience the festival all over again with Shiro-san.
Presumably, in the world's official timeline, the first one with Alice would be the one that 'stuck,' but Shiro-san and I would retain the experiences and memories of both. It was probably something like that.
"By using this Super WIN System, even one-day events like Christmas in your world can be increased to match the number of lovers you have. It is a revolutionary system."
"...I... I see..."
As expected of an almost Almighty God, the scale of her actions was so vast that I couldn't even keep up with my own retorts. And the troublesome thing was... I had a feeling Kuro and my other lovers would actually support this Super WIN System. On top of that, it did have the advantage of saving me from agonizing over who to spend seasonal events with.
The only downside was that I alone would have to repeat the same event as many times as I had lovers. It was a system I'd really rather not use too often...