give them sandwiches

sandwiches and duel them until you see a big heart on the thing that show you how many
time you have won or lost to them

easy really, when you want to target someone as your partner you ask the other characters
about rumors. Find out what the character you want to be your partner wants to talk about
that day, or doesn't want to and talk about. Talk to them about that everytime they go to
a new location that day. Also give them the type of sandwich they like, all of them love
the golden egg sandwich btw. here's a list of the sandwiches each like.

Jaden- everything
Syrus- Fried Shrimp
Chumley- Fish stuff like lobster & salmon
Alexis- Sweet stuff(jam,cream, chestnut)
Zane- plain(the kind you get the card in)
Princeton- Fancy stuff(caviar, goose liver)