Miiverse blocks those aged 12 and under from sending or receiving direct friend requests
Following their ever-present strategy of protecting folks on their online services, Nintendo has announced that anyone under the age of 12 will be unable to directly friend request (or be requested by) other users via Miiverse, and will instead have to manually input Nintendo Network IDs via the Home Menu. This doesn’t come as much of a surprise given their past with online security, and since it doesn’t affect the majority of users who would be interested in requesting each other (or the majority of people who own a Wii U already) they’re probably not expecting too much backlash.
– Miiverse Code of Conduct
Sounds like a safe plan to me!