Suzushiro: I have brought down the bird in the sky.
Angela and Arata, Back-to-Back Badasses. Add Glen and Shizuka you have one of the most inspiringly desperate fight scenes in the game.
Followed up rather shortly by the introduction of Crimson Iris, Arata and Angela's Fusion Dance form, taking the Curb-Stomp Battle the group was victim to and completely reversing it.
Angela and Liliana, during their battle. The latter for refusing to go down despite the damage she sustained, while making clear that she really is the most experienced and battle-hardened combatant in the Waltz, by displaying a lot of different techniques, culuminating in that awesome finishing attack. The former, for almost matching up to Liliana, refusing to stay dead after that finisher, and inventing a whole new finisher (on the spot!) based on what she saw during her battle with Iris.
Arata and Suzushiro's meeting in the park in the second half of the game. Suzushiro vs Arata? Suzushiro vs Arata? And ironicly enough he pulls off the same feat as she did previously, and wins!
The entire endgame scene where Arata has revived Chris, and together they summon the Eldhi Arc sword and kill Eldhin once and for all with the kickass theme song playing in the background.
Also, the scene with each princess after the fight with the Super Elder Guardener. The Finishing Move each of them pulls off there will blow your mind.
Meta-CMOA should go to the whole game. It's the only other H-Game to date (besides anything from the Nasuverse) that is chock full of Badasses, the h scenes actually make sense and add to the story, and features gameplay elements so good you could actually make an entire game out of the battle engine alone. Bonus points for the fact this game would make for one hell of an anime.
In the backstory, when Nanae gets pregnant. She's forced to drop out of the Waltz, at which point the father barges into her castle, explains that he's actually the God of Fangs, and that he's going to take complete responsibility for what happened. She throws him out on his ass. Allow me to repeat that for emphasis: Despite (or, perhaps, because of?) her pregnancy, she trounced a physical god. No wonder Shizuka grew up to be such a badass!
Twice in the first part of the game, while Chris is fighting an enemy she can't beat, Arata charges headlong into the fray (the first time armed with a fire extinguisher). Chris just looks on in shock. Granted, neither time goes especially well for Arata alone, but it's still awesome seeing him charge a Guardener to save Chris, even scared out of his mind. And then, of course, they join into Iris. Asskicking ensues.