1boy, solo, male focus, (@dang0:1.5), (@jacknife:0.8), novel illustration, manhwa, male, kang doyoon, school uniform, classroom, sunset, red sunset light streaming through window, standing at teacher's desk, looking back over shoulder, eye contact, startled expression, frozen like a cat, blushing, ears red, holding a half-crumpled letter in hand, afternoon glow, empty classroom, wooden desks, nostalgic atmosphere, score_9, score_8_up, score_7_up