Since the "no-heel" Rebellion series, Mizuno has seemed quite willing to experiment with all kinds of out-there designs.

Mizuno recently submitted a new racing shoe to World Athletics, designated DEV-HWS. HW corresponds to the HYPERWARP series — does the S stand for Spray? (purely joking)

The shoe’s most eye-catching feature is its spray-knit upper; it’s unclear how its performance will differ from the Light Spray upper technology.

From the approval photos, the midsole looks somewhat similar in that sponge-like texture to the current EVO 3 foam, and the density appears extremely low.

The foam thickness at both forefoot and heel is also substantial. But that foam is likely engineered for a few high-level races rather than for durability.

With last year’s pre-marathon launch of the new racing flagships HYPERWARP PURE/ELITE, Mizuno stopped trying to game World Athletics’ midsole measurement loopholes.

By using the MizunoEnerzy xp midsole for extreme lightness and rebound, they returned the racing shoe midsole to a single-piece construction, making it easier for a broad range of runners to handle.

For the full-carbon HYPERWARP PURE, a size 41.5 weighs around 137 g — in the “first tier” of lightness.

This DEV-HWS could very well, thanks to its ultra-light midsole plus an already very light spray-knit upper, hit the 100 g mark in the same size, or sit on par with the EVO 3.

Photos from other angles haven’t been revealed on social media yet, so the shoe’s performance characteristics remain a mystery.

But given the lively racing feel of the HYPERWARP PURE/ELITE, this potentially lighter, more springy “HWS” is definitely worth anticipating — it might even push Mizuno back onto the running world’s trending topics.