The Summer Scare Event, in fact, can be traced back to the Heian period and is an activity combining both entertainment and custom.
Because there are many summer monogatari stories in Japan that involve supernatural phenomena, the Summer Scare Event is essentially held in the summertime.
Just recently, Beichuan Si participated in Kyubei High School's camping activity scare event, which is one of these types.
Now, in the words of Nakazato Jing...
It seems they had held a small scare event in private a few weeks before, and it was in that scare event that Inuzuka obtained that cursed object known as the Box of Calamities.
After Nakazato Jing had calmed down a bit, Beichuan Si finally opened his mouth to confirm,
"The scare event has a direct connection with the Box of Calamities, right?"
"...Yes."
