Kohaku and the Hanafuda Tradition Behind a 2018 Jump Bonus

Dr. STONE Kohaku Hanafuda Card — 2018 Weekly Jump Magazine Bonus

Inside a Weekly Shonen Jump Bonus Card

This is an officially licensed hanafuda-format card that Shueisha, the publisher of Weekly Shonen Jump, distributed as a bonus insert in a 2018 issue of the magazine. It was not sold separately — readers received it by buying that particular issue. The card carries the Shueisha imprint on its face, marking it as a direct official release. Because it traveled through magazine distribution rather than toy or hobby retail channels, it never had a formal path outside Japan.

Perforations along both edges of the card indicate it was originally part of a larger printed sheet bound into the magazine. Readers removed it themselves — a standard format for Jump’s insert bonuses. Whether this card was accompanied by others on the same sheet cannot be confirmed from the card alone.

The illustration shows Kohaku, one of the leading characters from Dr. STONE, in a chibi (super-deformed) style. She is depicted seated on a large leaf, surrounded by purple star-shaped flowers and dark buds — visual elements that echo the plant and flower motifs found in traditional hanafuda decks.

Kohaku, Warrior of the Stone World

Dr. STONE is a science-fiction manga written by Riichiro Inagaki and drawn by Boichi, which began serialization in Weekly Shonen Jump in March 2017. The story begins with a mysterious light that petrifies every human being on Earth. Thousands of years later, a scientifically brilliant teenager named Senku revives and dedicates himself to rebuilding civilization entirely through science. The series built a devoted readership by weaving real concepts from chemistry, physics, and engineering directly into its plot.

Kohaku is among the first characters Senku encounters after his revival. She belongs to a village of people descended from those who survived the original petrification event, and the narrative describes her as the strongest warrior in that community. Blonde-haired and blue-eyed, she becomes a central figure in Senku’s group, handling the physical confrontations that scientific genius alone cannot resolve. Her personality is direct and action-oriented. The 2019 anime adaptation, produced by TMS Entertainment and distributed internationally through platforms including Crunchyroll, introduced the character to a wider global audience. This card, produced in 2018, predates that adaptation by a full year.

Hanafuda Cards and Manga Culture

Hanafuda are a traditional Japanese card format with origins in the Edo period. A full deck contains 48 cards organized into twelve suits, one for each month of the year, each represented by a seasonal plant: pine, plum blossom, cherry, wisteria, iris, peony, bush clover, pampas grass, chrysanthemum, maple, willow, and paulownia. The cards are used in several games, with Koi-Koi among the best known. Nintendo has kept the format alive as a product line for well over a century.

In more recent decades, character hanafuda — decks or individual cards that pair the traditional imagery with anime and manga art — have become an established part of Japanese fan merchandise. The Kohaku card follows that pattern: it retains the plant-and-flower visual vocabulary associated with hanafuda while centering a chibi character illustration. As a magazine bonus rather than a commercial product, it represents a version of that genre aimed specifically at Jump’s readership during a particular moment in Dr. STONE’s run — before the story had ever been animated.