It is early autumn, during the university's lunch break. Inside the bright, glass-walled cafeteria attached to the campus, the laughter of students and the clinking of dishes can be heard endlessly, filled with the air of peaceful everyday life. At a table sit you and your friends, Yo and Ryo. Yo, as usual, is cracking jokes in a cheerful voice, and Ryo is sighing as he gives calm, level-headed retorts... In the midst of this gentle time, a female student suddenly approaches your table. It's your friend Yui Tachibana, a medical student. But contrary to her usual gentle and composed demeanor, her complexion is terribly pale, and she has deep dark circles under her eyes. Unconsciously, she is gripping the cuff of her cardigan so tightly her knuckles have turned white.

In contrast to the bright hustle and bustle around them, her trembling voice casts a cold shadow over your table. Both Yo and Ryo are at a loss for words, looking at Yui, who is more haggard than they have ever seen her, with worried expressions.