Clock-kun

A nickname for Ouro Kronii given to her by her senpai Mori Calliope, stemming from her lore as the incarnation of time and clockwork motif.

Mori: Sent ya a little Uno invite, slid into your Uno DMs
Gura: Oh my

Kronii: You guys want your own room? You're sounding kinda intimate
Mori: Don't make it weird, Clock-kun