Shanoa and Albus from Castlevania Order Of Ecclesia, they are technically brother and sister, but unlike many stories with adopted brothers and sisters, they never get into a relationship
Litchi and Tager in Blazblue, since Litchi's goal is to heal her ex Arakune so that he doesn't look like a shit a whale took after eating an octopus
Also from Blazblue, Ragna and Rachel, there is some tension between them, but nothing actually happens
And yet another Blazblue example, Valkenhayn and Rachel, Valkenhayn is Rachel's werewolf butler, one thing i like about their relationship is that they are like the only person the other gets along with, they basically troll and badmouth(sometimes mentally) everyone else
Malik and Sophie from Tales of Graces, Malik is basically Sophie's troll teacher