It definitely accomplished its comedic goals, if nothing else. I thought this final episode was a lot more funnier than the previous ones.
Ultimately, they both went further but also didn't go as far as I expected. Kosuda getting as far as finding her hole took me by surprise as I was convinced the last episode's breast fondle was the hottest we'd get, but I would have thought at least they'd end with a confession, or acknowledge each other as partners.
In any case, a fun series with solid adult comedy. My only regret is not seeing a sexually suggestive Kyouka.