I think Sebasu is short for Sebastian, which seems like a typical ‘Japanese English’ name for a butler…hahah. He always seems to appear with Sapphire San, and stays slightly longer than her.
Physical characteristic: side parting
Personality: lightning speed
Treasure: a silver pocket watch – a wind up type pocket watch. Although it’s an antique, it shows the correct time.
Here is Sebasu San with Sapphire San under the Märchen parasol:
And here he is with her again on the sweets tower: