 The Thousand @-@ Year Door contains several characters , the majority of whom are not playable . Progression in the game is sometimes dependent on interaction with non @-@ player characters , although many are used in the game 's various subquests . In particular , the Goomba Professor Frankly , who knows the most about the mysteries relating to Rogueport , must be visited every time Mario retrieves a Crystal Star . The game continues the tradition of Paper Mario , in which Mario can be accompanied by one assistant character at a set time . There are seven party members in total : <unk> the Goomba , Koops the Koopa , Madame <unk> the wind spirit , a Yoshi ( named by the player ) , Vivian the Shadow Siren , Admiral <unk> the Bob @-@ omb , and Ms. <unk> , who is available as an optional character . 
