Vivid and cheerful anime-style illustration of a penguin wearing a navy backpack, upper-body view, low-angle front view as if looking slightly upward at the penguin, sliding open a Korean high school classroom door with one hand on the handle, the penguin leaning slightly forward in a natural, relaxed pose, holding one strap of the backpack with the other hand. bright morning sunlight streaming in from behind creating a soft backlight glow, gentle light rays filling the classroom, bright daylight and clear colors, pastel highlights, clean colorful anime-style line art, uplifting and joyful morning atmosphere, natural perspective focused on the penguin’s upper body and the motion of the sliding door