Junior Smartphone Plan

This is a rate plan for the junior smartphone. The Upgrade Program (Junior) for switching models within 3 years is also included for free. This rate plan is for kids in elementary school and younger.

Application Required


Monthly basic charge When 2-year contract [1] is applied ¥3,620
Before application for various discount services ¥4,620
Domestic calling charge To au mobile phones Free between 1:00 and 21:00
¥20/30 sec between 21:00 and 1:00
To other carriers' mobile phones or landline ¥20/30 sec all day
Data communications charge A monthly data amount of 2GB [2] is included in the basic charge.
Domestic SMS (C-mail) To au mobile phones Free
To other carriers' mobile phones and PHS Sending: ¥3/time
Receiving: Free
  • [1] 2-year contract is automatically renewed in two-year units. In the case of contract termination, a contract cancellation fee of ¥9,500 is incurred (excluding the renewal period). Smile-heart Discount is also eligible.

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Eligible models and subscription conditions

Subscription is available only to users who are in elementary school or younger at the time they subscribe to the plan and purchase the miraie f or miraie.

miraie f


Free benefits

Upgrade Program (Junior)

When switching to your next model, the remaining amount for the installment payments of the miraie f or miraie is essentially free.

<Applicable conditions>

18 installment payments have been completed after the purchase of a miraie f or miraie with a 36-month installment payment contract.


You can apply at an au shop / au Style.

Universal service system

In accordance with the launch of the "Universal Service System", KDDI has begun imposing a "Universal Service Fee" on customers who signed contracts with us for their portion of usage since January, 2007. See below for the details.

Universal service system


[About the Junior Smartphone Plan]

  • * This plan cannot be used with models other than eligible models. Also, this plan is not eligible for the Student Discount or the Extra Option.
  • * When applying at the time of making a new subscription or switching models, this plan becomes applicable from the date of subscription or the date of switching models. Charges are prorated in cases where you cancel a contract before the end of a month.If you are subscribed to 2-year contract and cancel Junior Smartphone Plan, calculation on a prorated basis is not applied and the flat rate is incurred.
  • * For calls that straddle the 9:00 pm or 1:00 am time designations, charges are waived for the time segment straddling the time designation (30 seconds). Calls to special numbers including the Answering Service (Voice Mail) (1417) do not count as free calls. If KDDI determines that your call is continually long or it is affecting other calls, we may disconnect that call.

[About the Upgrade Program (Junior)]

New applications are no longer accept as of September 30, 2019.

  • * If you purchase the device with a single lump payment or from the au Online Shop; change rate plans, collectively pay the installment amounts; transfer, suspend, or cancel your line; or change your model before the 17th installment payment, this program's benefit does not apply.
  • * This program's benefit is available for the amount remaining after the 18th payment.
  • * After changing models, the remaining installment payments are continued to be billed. However, the remaining installment payments through this program are discounted monthly from the month you change models making the amount you pay essentially zero.
  • * If you change models using this benefit, you must return your current model and continue subscribing to the Upgrade Program (models are limited).
  • * The following types of models are not eligible for return and are not subject to use of the benefit. (1) The power does not turn on; (2) The charging lamp does not turn on when charging; (3) The body or screen of the phone is damaged or cracked; (4) The passcode lock is not cancelled and the phone has not been completely reset; (5) There is a response to water leakage stickers placed in manufacturer-designated locations; (6) The serial number cannot be confirmed, the device has been modified, or other circumstances that void the manufacturer warranty
  • * Backup of data and initialization of the device being returned is the responsibility of the customer. After the device is returned, all data is deleted and cannot be recovered.
  • * When returning, remove all memory cards, straps, and other accessories. After returning, all accessories will be disposed of.
  • [2] [Restriction of 4G LTE/3G communication speed]
    • * If the total amount of communication exceeds the monthly data amount, the maximum communication speed for sending and receiving until the end of that month will be 128 kbps. (The communication speed restriction will be removed on the first day of the following month.)
    • * To avoid network congestion, a limit may be placed on the communication speed for a whole day if you have used more than 6GB over the three most recent days (not including the day on which the restriction is applied). The restricted speed will differ depending on data traffic conditions.
    • * Regardless of whether you are subscribed to a data (packet) flat-rate service, your line may be temporarily suspended if the cost of the packet communications you use becomes high.
  • By phoneOpen 9:00 – 20:00

    • English

      0120-959-472(Toll Free)

    • Portuguese

      0120-959-473(Toll Free)

    • Chinese

      0120-959-476(Toll Free)

    • Korean

      0120-959-478(Toll Free)

    • Tagalog

      0120-933-952(Toll Free)

    • Vietnamese

      0120-933-961(Toll Free)

    • Japanese
      about au mobile services

      157(Toll Free)from au phones

      0077-7-111(Toll Free)

      about Internet services
      Contract / Fee / Billing

      0077-7084(Toll Free)

      Connection setting / failure

      0077-777(Toll Free)