This time I still write ancient male essays. I actually like this couple quite a lot, but the background is not the time when they went to the Demon Realm. Maybe it was the time when they were playing volleyball? Anyway, you can ignore the background. In short, Oga discovered Furuichi's secret one day, and then all kinds of things happened to Furuichi because of Furuichi's secret, right? Perhaps. . . . Maybe the character's personality is broken, so give it a pat.