I feel ambivalent about their dynamic.
You can tell Yuu's a good dude and he truly wants to support her. But at the same time he just... doesn't get it. He came from a loving family and he's projecting that onto her family situation. He reasons that he can "save" her just by giving her a normal life.
It's kind of a mirror to how Airi feels about Hirokazu and how she saw parallels in her own life with him. She wanted to "save" him by teaching him to cope with his trauma in the same way she does. Obviously Airi/Hirokazu's dynamic was obviously far, far, FAR more fucked up than Airi/Yuu's, but you can definitely see parallels there.