Toss Bank Reveals 9 Squirrel Characters and UI Design for AI-Powered 'Grow-it Savings'

Toss Bank's Grow-it Savings has been restructured so that characters grow only when users save daily. To support this, AI image generation tools were used to create 9 final evolved squirrel characters. From an initial pool of 101 "trainee" drafts, 9 squirrels with distinct personalities based on Charm, Wisdom, and Strength stats were selected as the debut group.

AI-Based Character Creation and Detail Refinement

Designers used node-based AI tools to set up common prompt templates and character-specific variables to improve efficiency. While the selection rate initially dropped from 1 out of 100 to 2–3, manual refinement of key details such as expressions and silhouettes remained essential to adapt AI outputs to the small screen size within the app.

Character-Centric UI Design System

Moving away from simply overlaying characters onto the existing UI, a dedicated design system was built where the character is the protagonist. The total saved amount is prominently displayed at the top of the screen, levels and stats are integrated into a single status bar, and choice icons are matched with status bar stat icons to enhance intuitiveness.

Interaction Design to Encourage Daily Visits

Immediate feedback is provided through motions where amounts and stats rise instantly upon saving, with the character reacting accordingly. Additionally, footprint icons on the progress bar visualize the days remaining until the next evolution, motivating users to revisit the app daily.