Have to say
Nico Robin to the first 3
Ippo's mom for a mother figure
orihime inoue for a nurse (maybe I can get healed faster lol)
since I only know the OP characters I'll go with vivi as a little sister. Though Nico Robin could be an interesting older sister.
It's a toss-up between chichi and sakura for least desired to hang out with.(flips coin. Ok, sakura wins)