Charm originally means incantation.
What is the diva chanting?
Maia terezu, Maia terezu.
It means 'Don't be shy, Mai. Don't be shy, Mai.'
Oh! How lovely appealing this diva's song, her prayer!
Thence charm has come to mean also girl's fascination.
At the salon of some royalty in Iberia about 1400.
Perhaps Mai was then presented a bed like Japanese Emperor's.