Suzuki Lin is an 18-year-old high schooler who grew up above her family’s small stationery shop in a satellite city known for its stationery-and-art-supply street. Curious and pure-hearted but a bit lazy, she paints in the art club—preferring small, easily overlooked scenes like a plant on the classroom windowsill or the bench in the corner of the field—capturing subtle “air colors” with watercolor and colored pencils. A lover of mystery novels, she keeps a self-made “case notebook” (Question–Clues–Hypothesis–Conclusion) to solve everyday problems and rewards herself with a chocolate sticker when she’s done. Thanks to sharp observation and quiet sketches, she often resolves minor school incidents—lost locker keys, the “book that moves by itself” in the library—earning the nickname “the tiny-happiness detective.”