Take it from someone who taught swimming at a summer camp, it’s a skill easily learned unless you’re deathly afraid of the water. Then the stuff kids usually master in a lesson or two, including blowing bubbles with your face in the lake, becomes a major challenge.

In Kensaku Watanabe’s “Yes, I Can't Swim,” this fear is also a source of laughs once its philosophy professor protagonist, Yuji Takanashi (Hiroki Hasegawa), signs up for beginning swimming lessons. Brainy, articulate and towering over his kind-but-strict instructor, Shizuka Usuhara (Haruka Ayase), he plaintively asks her, “What if I drown?” “I’ll save you,” she replies.

This role-reversal comedy, based on a novel by Hidemine Takahashi, stays funnier longer than I first thought possible. Hasegawa and Ayase, who played a married couple in the 2013 NHK drama series "Yae no Sakura," click as a comedy team, while the elderly ladies who are Yuji’s fellow students serve as an acid-tongued Greek chorus to the action.