The finale of the manga is this, as the last page announces out of nowhere that the manga has ended. Interestingly enough, it says that the creator only found out his series was discontinued when he went to a store to read it and found out it had been cancelled for TWO WHOLE MONTHS without him finding out.
In episode 17, there's an insanely random and hilarious visual gag when Takenouchi talks to Hayashida about his motion sickness problem. The two drink glasses of ice water as they talk, and after Takenouchi admits his problem, it cuts to a shot of Hayashida. For no reason, his glass of ice water is now gigantic and he's holding it with two hands. Then in the next shot, it's normal again.