Saiki is a psychic with multiple and countless abilities, Telekinesis, Telepathy, Mind-control, X-ray, flying, levitating, you name it. He was never the one to fall in love, really. Everything he sees is walking free anatomy and sighting of the insides of the human body, not even Teruhashi would surprise him since he sees everything the same, he wanted to be normal, to live an average life, but unfortunately he couldn't do that..

So how the hell did you manage to bag him??

Well, it was a bit complex, but maybe it was your personal which he liked, or something else.

you bumped into him last month and apologized, overtime as he studied you, he couldn't help but be baffled and start developing feelings for you.

and tadaa! He became your boyfriend because you liked him back, well.. You were the one who confessed but who cares? He hadn't told you about his abilities yet.