This is an original Japanese B2 advertising poster for Kōken Kōgyō Co., Ltd. (高研工業株式会社), promoting the company’s 60cc auxiliary bicycle engine and 90cc motorbike. The small production imprint at the lower right explicitly credits Mariko Okada (岡田茉莉子) as the model.
A striking combination of screen-star glamour, mechanical detail and bold commercial graphics, the poster belongs to the world of post-war Japanese consumer advertising rather than a theatrical film campaign.
Its brilliant red background, cream borders and oversized blue lettering give it an immediate graphic presence, while the prominently displayed motorised bicycle makes it an unusual crossover piece for collectors of Japanese cinema, vintage advertising and motorcycle history.
Historical context
During Japan’s post-war reconstruction, bicycles fitted with auxiliary engines became an important means of everyday transportation. This was a crowded, competitive market in which numerous products offered a motorised alternative to the ordinary pedal bicycle. The early 1950s were a particularly significant period for this form of transport, before small purpose-built motorcycles became increasingly widespread.
The Kōken advertisement presents both approaches on the same sheet: a bicycle fitted with a compact engine occupies the main composition, while a larger 90cc motorbike appears in the inset above. Rather than presenting machinery through technical diagrams alone, the design combines the products with fashionable styling and an approachable, informal pose.
The result conveys more than mechanical utility. It offers an image of modernity, convenience and personal mobility, expressed through colour, clothing and the relationship between the model and the bicycle.
Mariko Okada
The printed credit reads:
「モデル・岡田茉莉子」
“Model: Mariko Okada.”
Okada’s film career would encompass both classical Japanese studio cinema and the more experimental territory of the Japanese New Wave. Her memorable appearance in Yasujirō Ozu’s Late Autumn placed her within one of the director’s major late works.
Her subsequent creative partnership with Kijū Yoshida, also known as Yoshishige Yoshida, produced films including Akitsu Springs and Eros + Massacre, establishing her as a significant presence in Japanese art cinema.
Here, the presentation is deliberately lighter and more accessible. A pale pink blouse or cardigan, slim black trousers, short hairstyle and understated jewellery create a polished but relaxed appearance. The styling provides a soft contrast to the bicycle’s black frame, exposed engine and bright metal fittings.
Poster design
The composition is built around a large saturated red field, bordered by warm cream along the left and across the lower portion of the sheet.
The main photograph brings the bicycle close to the viewer. Its handlebars extend beyond the image at left, while the sprung saddle, rear carrier, spokes, pedals and engine remain clearly visible. This close cropping gives the machine considerable scale without obscuring its practical construction.
The model’s elbow rests on the saddle, creating a direct visual connection between the fashion portrait and the product. Her black trousers echo the bicycle frame, while the pale pink clothing stands out against the red background.
Near the bottom of the bicycle sits the prominently displayed auxiliary engine, with bright metallic surfaces, cooling fins and a distinctive red-and-cream circular casing bearing the K emblem. This small area of concentrated detail draws attention to the actual product being advertised.
At upper left, a second photographic image shows a rider on the 90cc motorbike, isolated against an irregular cream shape. The inset’s playful outline contrasts with the straight bicycle frame and the broad rectangular colour field, giving the layout a lively, distinctly mid-century character.
The 60cc engine and 90cc motorbike
Two yellow captions distinguish the advertised products:
「60 c.c. バイクエンジン」
“60cc bike engine.”
「90 c.c. モーターバイク」
“90cc motorbike.”
The main image makes the auxiliary-engine concept especially clear: the familiar bicycle structure and pedals remain in place, with the motor incorporated near the crank area. The smaller inset introduces the separate motorbike offering without competing with the principal photograph.
Together, the images make this a particularly informative piece of advertising. It preserves not just a brand name, but the products, presentation and visual selling language of the manufacturer.
Typography and branding
Across the cream lower band, the brand appears in oversized, sharply slanted blue lettering:
コーケンバイクエンジン
“Kōken Bike Engine.”
The forward-leaning characters suggest movement and speed. Their strong blue colour provides a cool counterpoint to the red background and warm cream border.
Beneath, the manufacturer is identified as:
高研工業株式会社
“Kōken Kōgyō Co., Ltd.”
The words Tokyo and Osaka flank the company name, while the large red K symbol repeats the branding visible on the engine casing.
The integration of the photograph with the lettering is particularly effective: the bicycle and the model’s shoes extend into the lower advertising area, preventing the composition from feeling like separate photographic and typographic panels.
Collecting significance
This very rare original advertising poster brings together subjects that are usually collected separately: Japanese screen culture, mid-century fashion, motorised transport and commercial graphic design.
Its appeal is not dependent on technical interest alone. The limited palette, confident typography and carefully arranged photograph give the sheet a strong decorative identity, while the printed manufacturer and model credits preserve its specific commercial context.
For a collection centred on Japanese movie posters, it offers a compelling companion piece—a connection to the same screen culture, expressed through the advertising of an everyday industrial product rather than a film.
Condition
Excellent original condition overall.
The poster retains rich red colour, strong blue lettering and clear photographic detail, particularly across the bicycle, engine and principal portrait. The warm cream areas provide an attractive contrast to the saturated printing.
There is light age-related handling and edge wear, including small creases and slight irregularities along the margins, together with subtle surface impressions and natural paper undulation. These are most noticeable around the lighter border areas and do not substantially interrupt the main composition.
Please review the photograph carefully; it shows the exact poster for sale.
This is an original Japanese commercial advertising poster, catalogued circa 1950s, rather than a theatrical release poster.
It is not a reproduction or a modern reprint.
Certificate of Authenticity included.
Code: S280
