Rakuten Mobile Japan

Rakuten Mobile bundles eSIM with automatic international roaming that activates the moment you land in Vietnam, with no separate purchase needed. The carrier unifies data, calls, and SMS into one bill, keeping track simple while traveling across Southeast Asia.

Best for travelers coming from Japan or those with existing Rakuten subscriptions who want a single account to manage. The predictable per-day approach suits people who prefer knowing their roaming cost upfront rather than monitoring usage to avoid overages.