A Genius in the Forest Strays for X

It’s the Ichinose Academy’s famous two-night, three-day intensive study retreat. Nariyuki and the group concentrate on their studies in the mountains, but Rizu for some reason is constantly distracted by Nariyuki. Seeing Nariyuki have fun with Fumino and the others puts her in a bad mood, until at last she loses her temper and decides to run away.
Later that day, Nariyuki hears from Sawako that Rizu is nowhere to be found. He searches for her all around the area amid the pouring rain, before finding her on a cliff. Nariyuki reaches out a hand to help Rizu, but she loses her footing...