Received birthday letters in the mail/when KK Slider sung from random strangers?

[Jhine7]

Today is my birthday and KK Slider showed up to sing.

When he was singing, a bunch of messages showed up, mostly from villagers wishing me happy birthday.

HOWEVER, I received 2 messages from random strangers that I am NOT friends with and never heard of. 1 being "monza from corndog".

Afterwards, I received this message and another one in a different language, in the mail. I'm very confused on where these came from. In the end, oh well, but very interesting.

 

[Leo King]

Today is my birthday and KK Slider showed up to sing.

When he was singing, a bunch of messages showed up, mostly from villagers wishing me happy birthday.

HOWEVER, I received 2 messages from random strangers that I am NOT friends with and never heard of. 1 being "monza from corndog".

Afterwards, I received this message and another one in a different language, in the mail. I'm very confused on where these came from. In the end, oh well, but very interesting.

Happy birthday! That's pretty weird, I wonder if it's a glitch?

 

[dizzy bone]

If you had random traders or friends in your town on your birthday and they spoke with KK they can leave you a birthday note. If you didn’t have visitors on that they for them to leave notes... well then that’s weird

 

[Hobowire]

happy bday.

 

[Jhine7]

If you had random traders or friends in your town on your birthday and they spoke with KK they can leave you a birthday note. If you didn’t have visitors on that they for them to leave notes... well then that’s weird

No random traders or friends have visited today, very weird!

 

[Roxxy]

Happy Birthday

 

[kylie32123]

Happy birthday to ya!

 

[OswinOswald]

Happy Birthday!
I heard it could be from anyone who visited you in the week or so before your birthday. Or maybe it's within a certain number of KK visits leading up to your birthday. My birthday was on a Monday, and someone who had visited me for turnip selling 10 days prior had written me a birthday letter. (I found them by looking through friend suggestions on my switch, you can see 'Users you have played with' and the date and time of their visit)