Fireflies are flying and glowing fantastically. Patterns of firefly squids, 'yakoutake' (glowing mushrooms; Mycena chlorophos) and 'owankurage' (crystal jelly; Aequorea victoria) are seen on kimono. They share a common mechanism in which a class of chemiluminescent substrate (luciferin) is oxidized and excited by the catalytic function of a class of enzymes (luciferase), and light is emitted as a result. There has been a custom of appreciating the glow of fireflies in Japan since ancient times, however, it was possible only for a short period in early summer. Life scientists today are lucky to admire the chemiluminescent signal throughout the year. The structural formulas in the sky, and on the woman's and child's round fans are those of firefly luciferin, its dioxetane derivative and excited oxyluciferin, respectively.
May in the old Japanese luni-solar calendar is a season when flowers of 'hanashobu' (Japanese iris, Iris ensata var. ensata) are in full blossom by the waterside. In the pond in this garden, clusters of hanashobu can be seen. Oh, watch carefully! Some flowers in front of us are made of α-helices and β-sheets, aren't they?