Yo, Keine, you forgot your lunch.

Aren't you two all chummy again today!

I know! This is what you call a "mandarin duck couple", right?! A term for a loving couple, as mandarin ducks are famous for their monogamy

Now, Cirno, don't tease us.

Mokou isn't such a heartless person, right? ♪

However, they say actual mandarin ducks can be polygamous, and once their children are grown up, the male will go and have affairs with other females.