Dang so his name really is Uranari?
Exactly that. His last name is 浦成 and it sounds exactly like “Uranari.” It's a real surname, though a rare one. But both Akemi and the owner of the standing bar refer to him using katakana (ウラナリ) -- that is, by that somewhat insulting nickname.
The first kanji (浦) means “shore”—and he lives by the water.
The second (成) generally means “to bring to completion,” and, funnily enough, that very same 成 appears in the word 成績—“academic performance, grades.” Yet he can't into uni for three years now.
Tsuyatsuya-sensei loves linguistic jokes.