That's not really the case though. Kuroyuki implied that she is very ashamed of her robotic battle form, Black Lotus, even calling it an abomination. If she sealed it, that means she will be unsealing it at some point.

I like the dynamic between the two of them. Kuroyuki always being a bit flirty with him (which bothers her own classmates as well as Chiyuri). At this point I can't really say what she likes so much about him, since she seems to have been attracted to him since she met him at the squash courts. It's not clear what she wants him for (defeating her I wonder?), but it certainly did feel like she was confessing to him, and he refused in his very humble and polite way. He's got such low self-esteem, but the two girls must see something in him that we haven't been shown yet.

Maybe she loves to cuddle his pudginess, in little piggy form and made real life.

I do love that his ultimate attack is just a headbutt, and a really powerful one at that for how slow it is, and how simple the animation for it is. It one-shot KO'd the guy.

edit: oh, and a KOTOKO ED. hell yeah!