The Slacker is a base student, so they can be bought in the Store using coins. It is possible to get a Slacker from a party using any combination of students, so long as at least one classmate has Slacker as part of their type.

How do you get different characters in high school story?

You will unlock these characters after completing certain quests. They cannot be customised and their clothing cannot be changed however, you are free to make them date whomever you wish and if you pair them up with another Main Story Character, this will change certain pieces of dialogue in sub-sequential quests.

How do you get Ellie on high school story?

Ellie is a Mascot All-Star in High School Story. She can be purchased for 300 rings and can be placed in either the Prep Hangout, Jock Hangout or Artist Hangout. She is unlocked at Level 6.