キーゾンv3 is a Chrome extension tool developed by sedori koubou. It is designed to display the monthly sales figures of キーパ (Keyper), allowing users to efficiently assess their purchasing decisions and make detailed judgments on the quantity of items to be purchased.

The main features of キーゾンv3 include calculating the rise and fall of rankings to determine the monthly sales figures, displaying information such as JAN code, model number, category, release date, availability of variations, and availability of Amazon stock. Additionally, it provides a detailed history of rankings, new items, used items, and collector's items.

With キーゾンv3, users can easily track the monthly sales of キーパ and make informed decisions about their inventory management. This extension tool proves to be a valuable asset for sellers and collectors alike.