SK Square has invested in Mujin, the Japanese developer of robotics control software, as the Korean investment firm pushes to connect its semiconductor portfolio with the emerging market for physical AI, Chosunbiz reported.

The deal marks a rare cross-border alignment between a Korean chip-focused investor and a Japanese automation software company. SK Square, spun off from SK Telecom in 2021 to concentrate on semiconductor and technology investments, holds a controlling interest in SK hynix, the world's second-largest memory maker. Mujin, based in Tokyo, builds motion-planning software that lets industrial robots operate without traditional teaching pendants — the kind of machine intelligence that physical AI applications demand.

Why does a chip investor want robotics software?

The reported rationale is strategic rather than immediately financial. Physical AI — systems where machine intelligence controls machines moving through the real world, from factory robots to autonomous logistics — consumes computation at every layer: training chips, inference accelerators, edge controllers, and memory. An investor sitting on memory and logic assets has a direct commercial interest in workloads that expand demand for those components.

Robotics software sits at the top of that stack. By backing Mujin, SK Square gains exposure to the application layer that determines how much silicon physical AI systems actually absorb, according to the report.

What does the deal signal about SK Square's direction?

The investment fits SK Square's stated mandate since its 2021 spin-off: move beyond passive chip holdings toward technology areas where semiconductors and software intersect. Key strands of that positioning include:

• Its controlling stake in SK hynix, a core supplier of high-bandwidth memory used in AI accelerators
• Portfolio investments across semiconductors and deep tech
• A stated goal of linking chip assets to downstream AI applications

The Mujin stake extends that logic from data-center AI into the physical world — factories, warehouses, and logistics, where robot fleets could become a major new class of compute customers.

How does the Korea-Japan angle play in?

The investment also crosses one of the industry's more sensitive borders. Korea and Japan have spent years managing export-control disputes tied directly to semiconductor materials, and cross-border capital flows between the two countries' tech sectors remain comparatively thin. A Korean investor taking a position in a Japanese industrial-software firm signals that physical AI is pulling the two supply chains closer, at least at the portfolio level.

For Mujin, Korean capital and proximity to SK hynix's ecosystem could open routes into AI-grade hardware. For SK Square, the stake is an option on a robotics market that Japanese manufacturers increasingly treat as a response to chronic labor shortages.

Chosunbiz did not disclose the investment amount, the stake size, or a valuation, so the financial scale of the deal remains unconfirmed.

Going forward, expect SK Square to treat Mujin less as a standalone bet than as a test case for whether physical AI workloads can translate into measurable demand for the memory and logic silicon at the heart of its portfolio.