Yea, most take a few years before they're adults. Though you can kinda speed up the growth so that you can have a juvenile ragurāji in six months, but that's only through intense competitive training where you train for hours each day and take on the gymleaders. There's talk that you can get one under six months, but no-one's ever proven it.

Training isn't easy, either, because it's dangerous. [She nods to the mightyena beside her.] Tsuyoi here's a sub-adult guraena, and if I kept training her, she could become and adult in another few months, but I... There's risks with adult guraena.

[They are very much like hyenas after all, and an adult female is a lot riskier than a male.]