This is how to beat the Janken bosses when you play against them, without having to fight them if you lose.

1st: Choose Rock in the first game, then Scissors in the second
2nd: Scissors, then Paper
3rd: Rock, Scissors
4th: Paper, Paper
5th: Rock, Rock
6th: Rock, Scissors
7th: Paper, Paper

(Must be done in that order from the start of the game, if you choose one different along the way all the rest will be different)