Files formatted as [Name]ver[Number].rar in Japanese online spaces frequently fall into several categories:

Given the name, it is likely a small-scale RPG or a simulation game. 3. How to Extract and Play (Ver1.0b.rar)

Run an anti-virus scan on any downloaded .rar file before extraction. If you can tell me: Where you found this file What type of file it is (game, text, etc.)

A small, specific-purpose application or simulation.

Indicates this is a refined version of the initial release, likely having fixed bugs or balance issues from "ver1.0a".