Rakuten Mobile is preparing a more selective roaming model in Japan.
The operator expects to keep using KDDI network access after September 2026. However, it will reduce that support where its own coverage is strong. The change marks another step in Rakuten’s move toward network independence.
From October, Rakuten Mobile plans to rely on KDDI only in selected areas. These include locations where construction needs more time. In other regions, traffic will increasingly move onto Rakuten’s own infrastructure.
This approach gives Rakuten more control over service quality and costs. It also supports its position as Japan’s fourth mobile network operator. Yet the shift carries operational pressure. Customers expect stable service during every coverage transition.
The two companies signed their roaming agreement in 2018. KDDI helped Rakuten enter Japan’s mobile market in 2020. That support gave Rakuten time to build coverage while serving customers nationwide.
Now, the balance is changing. KDDI president Hirokazu Matsuda recently indicated that current roaming support should end in September. Still, talks continue over limited roaming in sparsely populated rural areas. The companies have not disclosed the possible locations.
Rural coverage remains the most sensitive issue. Building mobile networks in low-density areas brings weaker returns. Operators must spend heavily while serving fewer users. For Rakuten, continued roaming could prevent coverage gaps during the transition.
At the same time, reliance on another carrier limits strategic freedom. It may also constrain marketing around network ownership. Rakuten therefore needs a careful balance between expansion speed and service reliability.
Rakuten Group chief operating officer Kentaro Hyakuno said the rollout acceleration was not only tied to roaming. The company had already planned faster network construction. It is now moving at maximum pace.
Rakuten has also brought part of the construction process in-house. This should help address Japan’s severe labor shortage. It may also improve rollout timing and reduce dependence on outside contractors.
Investment plans show the scale of the task. Rakuten expects to spend JPY200 billion on base stations in 2026. That equals about $1.3 billion. By the end of June, it had already spent JPY65.5 billion.
The spending covers several spectrum bands. These include 700MHz, 1.7GHz, 3.7GHz and 28GHz. Lower bands help with wide coverage. Higher bands can add capacity in dense locations.
The 28GHz band also supports advanced 5G performance in targeted zones. However, it requires more sites because signals travel shorter distances. That makes planning and deployment more demanding.
For Japan’s mobile market, the transition has wider meaning. Rakuten wants to prove a newer operator can scale effectively. KDDI wants to close a support role that began years ago.
The coming months will test both sides. A reduced roaming deal could protect users while encouraging competition. But any coverage misstep would attract immediate attention from customers and regulators.
