User Rank

User Rank will be unlocked after completing chapter 2. Rank of the player is the total levels of all cat units they have, this feature appears since version 3.0.0 of the Japanese Version

Before completing Chapter 2
Initial Level (+ value) upper limit:
 * Normal Cats: Level 10+19
 * Special/ EX Cats: Level 10
 * Rare Cats: Level 10 + 9
 * Super Rare Cats: Level 10+9
 * Uber Rare Cats: Level 10+9

Reference

 * http://battlecats.spica-net.com/explanation/rank.html