>>715042276
There are 2 theories, one with it being Manhattan's sire, Sunday Silence.
The other one involves one of its siblings passed away during the 2011's tsunami or something.

This one is a stretch but Manhattan Cafe was designed by k_suwabe also who used to be a big fan of the ghost sunken ship faction from KanColle so maybe the artist suggested a ghost theme for the character?

coffee

>>714066471
She's dark like my soul.