Tsutomu was raped by his own mother and turned into a gynophobe. Wakano most likely was in an abusive relationship/workplace/environment/a combination of all three and was taken out of the situation by the man who would eventually be her husband, only for him to eventually attempt to rape her. The emphasis here is Wakano herself said he only attempted it, the flashback also showed he never actually did the act - but it was enough to send her over the edge because it reminded her of everything she went through before she met him, and most importantly, because he broke his promise to her. Obviously she is at least a bit of an androphobe as well, and now these two are pitted together by fate, knowing each other's biggest wounds and sins. Although I want them to end up together and heal each other, I sure don't see how they can evade da popo forever.
It was cute seeing Wakano getting fussy about Tsutomu's wounds, and then getting pissed off at Tsutomu once again showing a traumatic reaction to her body, with him somehow managing to get it under control lol. They're definitely warming up to each other.