Kurono is proud to present our 2025 anniversary timepiece – the Jubilee Sensu EOL ‘白藍’. This is a definitive release for 2025. Not only is this our highly anticipated anniversary model, but this year’s will be a little more special in conjunction with Hajime Asaoka’s 60th Diamond Jubilee.
New Guilloché Dial in White-Indigo ‘白藍’ (Shiraai)
Hajime Asaoka brings back his highly successful Réserve de Marche‘ Sensu NOS’ – which sold out in minutes – in a bright metallic baby blue colorway formally named ‘白藍’ (Shiraai). This is the first time since the 2021 Seiji that such a similar colorway has been used. Its vibrancy is further accentuated on a silver-plated guilloche dial giving unparalleled lightplay. A chrysanthemum-like wave guilloche pattern radiates outward from the center of the dial, and is complemented by the iconic ‘Sensu’ (Japanese folding fan) guilloche at the power-reserve indicator. At the periphery, railway-track guilloché is complemented by high polished steel domes at each hourly mark. Unique Kanji script in black is painted at each hour marker to complete this unique dial.
End-Of-Life (EOL) Movement Modified by Hajime Asaoka
Last year’s ‘Sensu NOS’ used a new old stock NOS movement which is no longer available. The new Jubilee Sensu EOL ‘白藍’ leverages a discontinued cal.9133 movement that is end-of-life, and no longer made. Only a limited number of these EOL movements have been made available to Kurono, and we do not have access to more. Additionally, so as to achieve dial purity, modifications were made by Hajime Asaoka to remove the calendar window and its geartrain, making this finite movement even more unique.
Jubilee Cabochon in Precious Onyx
To mark his 60th Diamond Jubilee, a precious black onyx cabochon adorns the watch’s crown for the very first time. This new feature marks the rarity and limited nature of this year’s releases for the occasion of Hajime Asaoka’s 60th.
‘白藍’ (shiraai) White Indigo Dial Color
“Japan has a long-standing tradition of indigo dyeing, known as ‘Aizome’. Depending on the depth of
color, various names are used to describe the different shades of indigo. Among them, the lightest
shade is called 白藍 ‘Shiraai’ (literally “white indigo”). The dial of this watch is inspired by that 白藍
‘Shiraai’ hue.”
“What makes indigo dyeing unique is how the tone of the color changes with its intensity. When lightly
dyed, it takes on a slightly greenish tint, and as it becomes deeper, it gradually shifts toward a purplish
hue. However, since the watch dial is made of metal, traditional indigo dyeing is not practical. Instead, I
provided a piece of fabric dyed in actual shiraai as a color sample for the dial manufacturer, and a soft
lacquer finish was applied using pigments, with Prussian blue serving as a substitute.”
“Using Prussian blue as a stand-in for traditional indigo is, in fact, a historically rooted practice in Japan
like in ukiyo-e prints by Katsushika Hokusai, with the color subsequently dubbed as ‘Hokusai Blue’.
Prussian Blue was particularly effective for producing delicate, pale blue tones. In that sense, the blue
on this dial can also be described as ‘Hokusai Blue’.” ~ Hajime Asaoka
Unique End-Of-Life (EOL) Movement, Modified by Hajime Asaoka
Finding a Japan-made movement that exactly suits Hajime Asaoka’s design intention was incredibly challenging. Last year’s ‘Sensu NOS’ used a new old stock NOS movement which is no longer available. The new Jubilee Sensu EOL ‘白藍’ leverages a discontinued cal.9133 movement that is end-of-life, and no longer made. Only a limited number of these EOL movements have been made available to Kurono. There is no other Japan-made movement being produced that meets the needs of Sensei’s aesthetic requirement of the power reserve indicator (Sensu/fan) at the 10 o’clock mark.
Additionally, to maintain the purity of the dial design envisioned by Hajime Asaoka, modifications were made at his bench to remove the calendar window and its accompanying gear train. While sounding simple, such modifications are technically time-consuming and require certain watchmaker man-hours to be put in. This, together with the finite availability of the EOL movement, makes the Jubilee Sensu EOL ‘白藍’ even more unique.
Jubilee Cabochon in Precious Onyx
To mark his 60th Diamond Jubilee, a precious black onyx cabochon, highly polished by hand, adorns the watch’s crown for the very first time.
“I’ve always liked crowns with cabochons, and I thought the Jubilee was the perfect chance to incorporate it. There were several stone options to consider – like lapis lazuli – but that is a blue-toned stone. And since the dial is also blue, it wouldn’t have created much contrast. I felt the sharpness of black would beautifully completment the soft tone of the dial, so I decided to go with precious onyx.” ~ Hajime Asaoka
This new feature marks the rarity and limited nature of this year’s releases for the occasion of Hajime Asaoka’s 60th. This cabochon crown is a jubilee feature and will not be available after which.
Meticulous Attention to Detail for Lightplay
The Jubilee Sensu EOL ‘白藍’ benefits from Hajime Asaoka’s ‘Kaizen’ spirit of continuous improvement, which sees slightly better polishing of the box sapphire crystal and polished steel elements, while Kurono’s iconic hands continue to be bent by human hands and highly polished in steel to accentuate lightplay.
The dial takes on different personas depending on the time of day and the type of light source. Under yellow light, the dial takes on a bluish-green tinge that is warm and romantic, whilst under white indoor lights it transforms into something a lot more pure and composed.
We encourage customers to see the Jubilee Sensu EOL ‘白藍’ under bright daylight to see the scintillating effect of the dial.
Power reserve indicator
The recessed power reserve indicator in guilloche takes on the shape of a ‘Sensu’ or Japanese fan, creating a sunken effect that adds dimensionality.
“The beauty of mechanical watches, especially automatic ones, are that they quietly ‘steal’ bits of energy from our daily movement and use it as power. The power reserve hand clearly visualizes that. That’s where the charm of the power reserve lies, and I think that’s what gives it meaning.”
UNIQUE KANJI MARKERS
The Jubilee Sensu EOL ‘白藍’ incorporates unique Kanji hour markers. These logographic characters, fundamental to the Japanese writing system, are artistically expressed in Hajime Asaoka’s signature calligraphy style.
“This time, I deliberately replaced “12” with the Kanji “零,” which means “zero” in English. As for “7” (written as 質) I chose a slightly different character.”
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