Any character that you obtain from the gacha or events may not immediately appear on your roster, so please wait for a little while before checking your characters again.

Also, please make sure that you currently don't have any filters applied, because that will limit which characters are displayed on the list. To do so, go to [Filter Characters], then select [All] for the [Group], [Type], and [Side Story] categories.

If you've already tried the above and your characters still don't show up, please contact customer support by opening the Menu, then tapping [Support] → [Support].