I removed seiyuu_connection - and consequently yuuki_aoi - tags because they are misleading in the context of all four characters pictured here. Only Victorica and Madoka are voiced by the same seiyuu (Yuuki Aoi), the other two are not. We can only guess why exactly all these charas are pictured here and why not the others, but clearly it's not because there is some kind of seiyuu connection between all of them.