Brain Sumo is a two-minute-a-day brain-training ritual. Work through quick calculation, memory, and reflex exercises — the full roster inspired by classic brain-training games — then press a Japanese hanko stamp into your own calendar to mark the day.
Every session helps Grandma Ume run her little stationery shop:
• 13 playable exercises: calculations, Stroop-style color tests, mazes, memory, counting, and more, unlocked by collecting calendar stamps
• Brain Age Check — three short tests give you a kind, personal brain age
• Daily hanko stamp — press it anywhere on today's calendar square; its position and tilt are yours forever
• Streak-powered sumo rank ladder, from Maezumo all the way to Yokozuna
• Collectible milestone stamps in your own goshuin book
• A shop with hanko inks that recolor every stamp in the game
No pressure, no long sessions — just two minutes a day to keep your mind sharp and your calendar a little more yours.
A 2-minute daily brain workout — stamp your calendar, help Grandma Ume's shop.