うん

「コーヒーのお替わりいる？」「うん、ぼくのは少なめ、弟のには多めについでね」

"Do you want another cup of coffee?" "Sure, make mine on the small side but be generous with my brother's."

「軽くならいいけど」「うむ、では金的と目潰しは有効にするか？」

"If it's a light workout, OK." "Right, so will we allow crotch-kicking and eyeball crushing?"

う〜む、相貌から判断するに上海からか。

Hrmmm, to judge from their looks they might be from Shanghai.