A certain research institute.
Shitou took the two newly received letters and, without thinking, opened the one with clearly delicate handwriting first, following his usual practice.
It would normally take him less than a minute to read through a dozen or so pages of letter paper before tossing it aside. However, this letter was different. After quickly scanning the content from beginning to end, he returned to the first page and started to read through it again, almost word by word, following the strokes of the pen.
It took nearly an hour before Shitou carefully folded the letter and a delicate wooden box appeared in his hand. He cautiously placed the letter inside it, where there were already quite a few envelopes with letters written in the same handwriting.
After putting the box back into his "little warehouse," Shitou then opened another letter.
