/vi/ in Japanese is usually just pronounced as /bi/ (but can be differentiated in text as ヴィ (vi) and ビ (bi))
So this is basically a 'Who's on First?' joke, based on all of them having a Bi/Vi in their names.
Thank you very much
Pancakes!Viy Viy ViyPunishment time ♥That's Da Vinci-chan.That's Abby-chan.My dear Viy...Viy? Where could you have gone?Welcome in, Master-kun♪
Come to look through my store again?That's BB-chan.