Okusama ga Seito Kaichou! got an OVA with the release of the ninth volume. You can see and get the ninth volume here.
If an OVA and the ninth volume still wasn’t enough for you, the announcement of season season should definitely get you excited.
Here’s the PV.
Fansubs for this OVA might be a long time coming, so you can read the translation of the chapter it’s based on here.
The gist is that while putting up posters, Ui takes a fall and our MC hurts his hand rescuing her from a serious injury. Ui of course feels guilty and takes it upon herself to help him, including in the bath. The usual bath hijinks takes place. Except things escalate a bit with our MC getting a “handjob” of sorts. Unfortunately, no HD caps here, as most OVA’s get released as DVD’s.