Heterogeneity 4th Anniversary
Four years have passed since the release of the first production run of Heterogeneity in January 2022.
Created as the signature model of mowl Ambassador Kenta Kushiro, Heterogeneity has continued to evolve over time.
Throughout its history, the HG Series has expanded through a range of limited editions and derivative models, steadily building its identity.
Under the hashtag #mowlHG, we would like to sincerely thank everyone who has supported and played the HG Series over the years.
In this blog, we’ll look back on the history of the HG Series and provide an overview of each model and its design philosophy.
Starting Friday, February 6, commemorative products will be released via the mowl International Online Store.
Details regarding the release lineup will be announced on this page and across our official social media channels once preparations are complete.
The HG Series is built around Heterogeneity, the signature model of mowl Ambassador Kenta Kushiro,
which first went on sale in late January 2022.
The HG Series lineup consists of four models:
the monometal yo-yo Heterogeneity, the full titanium model Heterogeneity Ti,
the bimetal model Overgeneity (Prototype), and Heteron, a plastic yo-yo made from POM.
Across the HG Series, a moderate width that avoids over-following trends and smooth, effortless glide on the string are shared design fundamentals.
Another defining element of the series is its iconic angel-inspired artwork.
This carefully refined, detail-oriented design not only elevates each product’s level of completion,
but also leaves a strong impression of a cohesive world and identity as a series.
-Heterogeneity
This is the first and commemorative model of the HG Series, which launched in January 2022.
It is characterized by a strong sense of torque transmitted from the initial throw,
high stability achieved through a slim profile,
and smooth, controlled glide on the string.
Two artwork variations exist:
the OG Logo, engraved exclusively on the first release and limited editions,
and the Regular Logo, used on the standard production version.
Heterogeneity (OG Logo)
A bold, striking angel artwork is deeply engraved across the side face of the yo-yo.
The angel’s wings are based on owl feathers, a long-standing icon of mowl.
Heterogeneity (Regular Logo)
Compared to the OG Logo, this version features a more delicate and finely detailed artwork.
The circular logo, inspired by clouds along the outer edge of the dome, subtly incorporates an angel, a devil, and hidden lettering spelling “Heterogeneity.”
These concealed elements add a sense of playfulness and discovery to the design.
-Heterogeneity Ti
This is the full titanium version of Heterogeneity, released in January 2023.
Positioned as a top-tier model within the HG Series, it builds on the exceptional stability of the original Heterogeneity while adding the distinctly refined feel unique to titanium.
With its outstanding spin power and remarkable stability, this model delivers a performance that clearly stands apart.
The laser markings, which shift in appearance depending on the angle of light, give the yo-yo a sense of depth and elegance that cannot be achieved with other metals.
In addition, a special variant was released featuring color anodizing that highlights titanium’s natural texture—a first for a production titanium model from mowl.
The refined surface finish and the body’s rich, elegant coloration are layered with time-intensive color markings, creating a distinctive presence that changes its expression depending on viewing angle and lighting.
Even in retrospect, its level of completion remains undiminished,
and it has come to be regarded as one of the defining models that symbolizes the HG Series.
-Overgeneity(Prototype)
This is the bimetal model of the HG Series, featuring a 6061 aluminum body with titanium outer rims, released as a prototype in April 2025.
While preserving the core structure that creates Heterogeneity’s signature smooth glide on the string, this model adds enhanced stability and acceleration, further refining its support for technical tricks.
At present, this model exists only as a prototype run of 15 units,
each individually engraved with a serial number, and has not yet moved into full production.
Overgeneity is not simply a bimetal version of Heterogeneity.
It is a model that reinterprets and reconstructs what mowl Ambassador Kenta Kushiro is seeking right now, translating those demands into a new form.
Overgeneity is currently in its final tuning stage, and we look forward to sharing more details as it approaches release.
-Heteron
In November 2025, marking the first anniversary of the opening of mowl Osaka,
Heteron was introduced as a new addition to the HG Series—a plastic yo-yo made from POM.
By using machined POM, the inherent softness of the material translates into a smooth, comfortable feel that spreads across the entire yo-yo, creating a uniquely refined playing experience.
Development of Heteron began with a simple idea: reimagining Heterogeneity in a plastic format.
For years, mowl Ambassador Kenta Kushiro had envisioned a POM version of Heterogeneity, which led to the deliberate choice of POM over standard polycarbonate.
This decision was not driven solely by weight reduction or cost considerations.
Rather, it was the distinctively smooth, slightly dampened texture of POM, its low resistance on the string, and the way it gradually softens and settles with continued use—a “growing feel”—that aligned perfectly with the philosophy of the HG Series.
While broadly inheriting the shape of Heterogeneity, Heteron features an aluminum dome on the face, engraved with its iconic angel artwork, giving the plastic body a clear visual and conceptual link to the series.
To address potential power limitations, Heteron was designed with a larger diameter than Heterogeneity and a relatively heavier overall weight, ensuring sufficient presence, spin, and stability.
For its initial release, alongside the standard Regular Logo version, a Black-only, first-release limited “Heritage Edition” was also introduced.
The face features a circular logo derived from Heterogeneity’s Regular Logo,
creating a distinctive artwork that stands out uniquely against the Black body and gives the model a clear sense of exclusivity.
Comment from mowl Ambassador Kenta Kushiro
It’s hard to believe that four years have already passed since the release of Heterogeneity.
When we first prepared to launch Heterogeneity four years ago, there really wasn’t anything quite like it in the yo-yo scene at the time.
Because it was developed specifically as my personal signature model, I was honestly unsure whether it would be accepted by players.
But once it was released, I received so many comments like “The spin power is incredible!” along with a lot of positive feedback about the artwork.
I still clearly remember how genuinely happy that made me feel.
This 4th Anniversary release is something I believe will satisfy not only longtime HG fans, but also those who have discovered the HG Series more recently.
I truly hope you’ll pick it up and experience it for yourself.
Your continued support means everything to me, and it gives me the motivation to keep moving forward.
Thank you for your ongoing support of the HG Series.
— Kenta Kushiro
Heteron Kenta Edition
The Ambassador colorway, Kenta Edition, is being added to the Heteron color lineup.
The Yellow (Orange) and Purple combination—colors that strongly represent Kenta Kushiro—has previously appeared as an Ambassador Edition on models such as M, Plvs Vltra, and Hybrid, and now joins the Heteron lineup.
Featuring a yellow POM body paired with a purple hub, this colorway delivers a bold contrast and playful energy that clearly reflects Kenta Kushiro’s signature style.
The Kenta Edition is the only version to feature a blasted hub finish.
The matte purple core creates a look that feels subtly but distinctly different from other Heteron colorways.
While the difference may appear minimal, those who already own a Heteron are encouraged to compare them side by side and experience the nuanced changes in feel and response for themselves.
Heteron (White)
Combining a white POM body with a silver hub, this colorway creates a clean, minimal presence with a sense of clarity and quiet elegance.
The feel is light and gentle—almost like being suspended on a cloud.
Paired with POM’s naturally smooth, slightly dampened texture, it delivers an immediate sense of comfort from the moment you pick it up.
mowl Online Store
February 6th at 11:00 AM (EST)
About the Product
Due to the inherent characteristics of POM (polyoxymethylene), very small dot-like marks may appear on the surface during the manufacturing process.
These are a natural result of the material itself and do not affect performance or durability in any way.
We appreciate your understanding and hope you enjoy the unique qualities that come with this material.
