Oboro's harem plan is a Bi-Harem
Btw...
while chisaki given up and came back rom 'future' for the sake of everyone, hibari are somewhat dont care to others as long she with him...
Its actually a realistic decision, but still...
@Amoorhen - souta & lucoa are in master and familiar relationship thou
@TitanAnteus - family relatonship indeed, not treated as love one (yet, maybe). But even become a love one, its still gei (except one of them grow a dick, like @anon763 said)