Hei always takes the most inconspicuous jobs - so I'd guess either waiter or janitor.
Also, shouldn't the squirrel be tagged with 'Mao' as well, since that's his code name, and he's a recurring character? After all, Hei is still called 'Hei'.
—Tokyo...Junior high schoolers wear uniforms.Who are you?By blending in with the public...... you meant this?That's rational.What about you, July?What about the eldest son?My hair and moustache interfered with my work, so I changed them.Primary school student.If the second son is in primary school and the eldest daughter is in junior high...He's a working adult.I'm doing night work at Kabukichou.It's a rational line of work that wouldn't arouse suspicion, even of foreigners [like myself].
