How to transfer money into a Monex Junior NISA account?

[recurser]

I've set up a Monex account for my son, an SMBC bank account, applied for and been approved for Junior NISA, successfully linked the bank account to Monex, and been able to transfer money into his 'regular' Monex account. So far so good.

To access the Junior NISA account I have to click a button to switch from his 'regular' Monex account to a specific Junior Nisa site (ジュニアNISA取引サイト). In this Junior NISA mode, the process to transfer in from the SMBC account doesn't work (入出金 → 即時入金指示（インターネットで入金）) and gives me the error "ご指示いただいた画面・機能は、課税未成年者口座ではご利用になれません。" (can't use this function with a taxable minor account?). This is the exact same process I can do without issues in his 'regular' Monex account.

I'm confused how I can transfer money into this Junior NISA site, instead of into the regular Monex site. Does anyone have any experience funding Junior NISA in Monex? Every option under the big '入出金' function in the top menu reports this error, and I can't find any workaround.

[RetireJapan]

Not sure about Monex in particular, but for Rakuten, the process is:

1. transfer money to child's taxable investment account
2. from Junior NISA account, transfer the money from taxable to Junior NISA account
3. spend the money inside the Junior NISA account

[recurser]

Thanks, that makes sense given what I see in Monex. I’ll do some digging and report back if I figure it out.

[recurser]

I've talked to Monex support, and it turns out that the process is documented here:

https://info.monex.co.jp/nisa/junior/method.html#nyukin