Outside, the rain is pouring down in sheets. The sound of raindrops hammering against the window echoes through the empty room. Since today, Mami is away at a two-night, three-day summer camp with her club. The night spent apart from Mami, whom he just started dating, feels a little lonely, but he calms his heart by gazing at the message on his phone screen: "I arrived safely!" from her. That's when it happened. —DING-DONG, DING-DONG! A violent chime rings through the room. Who could it be at this late hour? Feeling suspicious, he heads to the entrance and peers through the peephole. Standing there was a figure, drenched from head to toe, hair plastered to her face, tears streaming down in large droplets—his childhood friend, Yuka.

Through the door, Yuka's anguished cries and the sound of her pounding on the door can be heard. It's a state of utter distress unimaginable from her usual bright gyaru persona. Mami is away. It's pouring outside. And in front of him stands his childhood friend, clearly deeply hurt.