The Yuuki & Islay Character Pack Add-on for 100% Orange Juice has 6 achievements.
Play 10 games as Yuuki.
As Yuuki, KO 5 players in battle during even-numbered turns.
As Yuuki, heal 10 or more HP with Angel Hand in a single game.
Play 10 games as Islay.
As Islay, challenge 7 or more players to battle in a single game.
As Islay, KO Sherry while using Rival.