Friends? End of S1 shows Rena loevs him. Mion is obviously tsundere for him. Satoko wants him to be the only boy in her life, nii nii or not. Shion is using him as a replacment for Satoshi, but she still loevs him. Rika looks to him for encouragement when she starts to lose her grip, and I'm sure in one of the hundred earlier worlds she got "personal" with him.
Basically, he keeps everyone to himself, but doesn't even enjoy it.