Here, we finally get a first hint as to why Taku has a bad feeling with that photo and hear the name "Sayagimori". If you know a little Japanese, you can probably already deduce that this is the name of a forest. (I can't help but wonder if there might be a real forest with that name somewhere in Japan... but at least according to Google, there isn't. Too bad. ;;;)
Comic transcript
Shiori smiles proudly.
Shiori: "Of course! Don't underestimate my memory~! So what exactly do you want to know?"
Taku: "I saw a photo of the club members earlier and can't shake the feeling that I've seen that scarred guy somewhere before. He seems... somewhat familiar in an ominous way? If that even makes any sense."
Shiori: "It actually does! You might have seen his photo on the news!"
Taku: "The news?"
Shiori: "Well, does the 'Sayagimori Incident' ring any bells?"
Suddenly, a memory flashes in Taku's mind.
Taku: "Ah-!"