read the title and i thought if this about someone who's the swimest, is there going to be someone who's swimminger?
anyway i really like how they exaggerate facial expressions, especially on page 32. and connecting to the turtle/tortoise and rabbit/hare motif, the "u" in "Uzuka" is "rabbit" (i checked the raws to see if the rabbit kanji was there and the furigana of his last name says うづか. i think you might've missed that.) and the "kame" in "Kameyama" is more obviously "turtle".