Throughout the course of his life, before the Mad Cyborg, Genos has always been described as someone who's an overachiever. The type of person who remains dissatisfied with good, often going to extreme lengths to attain their idea of perfection. The type of person who'd kiss the person of their dreams and wonder if it's just right enough. Perhaps he would remain the same type of individual if it had not been for the Mad Cyborg.

It's disquieting to acknowledge the fact that everything you have grown accustomed to, everything that you are, and everything that you own could easily be ripped away from you in one single moment. And when you are left with nothing but ashes for dreams and nightmares for memories, when your back is pushed up against the metaphorical wall, there are only two things you can do- push back or be crushed.

Reconstruction is an arduous procedure and even Genos understands that nothing can be quite the same even if he persists in piecing everything together- too much is lost. So, he pushes back.
He makes do.

A cyborg's body is jarringly different in comparison, though he is grateful that Dr Kuseno has taken great measures to ensure that he is reminded of the discrepancy as little as possible. His wrath fuels him, simmering with a heat and violence strong enough, he is able to disregard everything else. It's enough. It doesn't matter. All he needs is an absolute destructive force to put an end to a problem. He doesn't need, doesn't want, any human tenderness (that would hurt too much).

Then he meets Saitama and he reconsiders.
His Teacher is very much flesh and bone, unrivaled in pure power alone as of the moment.
But still smiling, grieving, feeling. Perhaps this sort of tenderness is still needed, maybe he doesn't have to give it up in his pursuit for greater strength.

Genos doesn't feel anymore- at least not in the way others do. He does not feel the gut wrenching sensation one experiences when they miss a step while walking down stairs, he does not feel hear in his cheeks when there are embarrassing moments, he would never be able to fully recreate the sensation of pins and needles when someone reveals that they cherish you. But even so, it is not a complete loss.

He knows how much pressure to exert when embracing others. He knows how deep to dig to release muscle tension, how to cradle, how to hold and how to assure. He feels the way skin gives way just slightly when he bites down against flesh, can taste the slightly tangy texture of skin mingled with sweat and blood. He knows the places to adorn with kisses of worship, areas to nibble and set nerve endings ablaze with pleasure, how to leave marks against their rightful locations so that he can hear every gasp, every stifled breath.

Bare minimum, compared to what others are capable of when it comes to sensory capabilities.
But if bare minimum can still evoke smiles and reverent sighs of a flushed faced lover writhing against bed sheets, Genos will do with bare minimum. For the time being.